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First generation mobile telephony systems using analogue signals, but with the digitisation of the control link between the mobile phone and the cell (transmission) sites.


Extension of 2G systems through use of 2.5G protocols providing additional features such as GPRS packet-switched connections and enhanced data rates.


Second generation mobile telephony systems offering better quality at lower costs to the consumer through the digitisation of the signal and supporting voice, low speed data connections and short messaging services. GSM is the most widely used 2G standard.


Third generation mobile telephony systems as result of further progress in cellular transmission technology leading to faster bit rates. 3G system capabilities include provision of high-speed data transmission and supporting multimedia applications that including mobile TV video services, video-conferencing and Internet access. The main differentiating feature of 3G from earlier mobile technologies is its ability to support video services.


4G (Fourth-Generation Communications System) is the next, as yet not formally defined, stage in mobile communications after 3G, with LTE (Long Term Evolution) as the favourite candidate standard. The 4G vision is a comprehensive and integrated IP world, in which users can receive voice, data and streamed multimedia “Anytime, anywhere” at very high speeds.

AAAA (American Association of Advertising Agencies)

An organisation representing the interests of advertising agencies in the US. Also known as “4A’s”.

AAC (Advance audio codec)

From MPEG-4. Is a successor to MP3. The very high popularity of MP3 and its incorporation into a large number of players, including CD and DVD players should, however, ensure MP3 longevity for years to come.

ABS (Australia)

Australian Bureau of Statistics. Australian government’s official statistical organisation responsible for conducting the census.

Acceptance/ installation rate

Percentage of homes out of the approached sample that is successfully recruited, installed and participates in the peoplemeter panel. In the case of addresses taken from an establishment or other survey, the acceptance/installation rate is calculated by multiplying the acceptance/installation rate from the approached sample (or "recruitment pool") by the response rate to the survey from which the addresses were taken. Precise operational definitions of the acceptance/installation rate can vary appreciably across different peoplemeter panels.

Access channels

US term for dedicated 'public service' channels set aside by cable companies for non-discriminatory access to the network by the public, government agencies or educational institutions.

Active peoplemeter measurement

Peoplemeter measurement that registers viewer presence by means of remote control push-button handsets, where panel members are instructed to press at the beginning and end of each viewing session. Each person (family member) belonging to the panel is assigned their own button for purposes of individual identification, whilst additional buttons on the remote control handset are reserved for recording guest viewing. Today, all peoplemeter panels collecting audience data for TV advertising and programme purposes employ active measurement.

Active/Passive (A/P) Meter

The Active/Passive Metering system actively reads video and audio codes embedded in the programme and is capable of producing audio signatures as a secondary identification method or as a back up.

Ad blocker (Online)

User software that prevents Internet ads from being displayed.

Ad download (Online)

Advertising that is downloaded to the user’s browser.

Ad impression (Online)

(1) Any form of Internet advertisement that is successfully served to a user’s browser. (2) Unit of measurement of Internet advertising. The total count of ad impressions denotes the number of responses from an ad delivery system to requests from user browsers, ideally recorded as late as possible in the delivery to the user’s browser in order to be closest to actual OTS (opportunity to see). A basic distinction exists between requests that are “server initiated” and requests that are “client initiated”. Server initiated requests proceed from the publisher’s Web content server, while client-initiated proceed from the user’s browser. Recommended procedures for ad counting differ in either case.

Ad request (Online)

Request for an advertisement coming directly from a user’s browser, as recorded by the ad server.

Ad server (Online)

Web server that stores and delivers online advertising to visitors at a Web site. Ad servers will also monitor the number of impressions/clicks for an ad campaign along with other recording and reporting functions.

Ad stream (Online)

Series of ads displayed during the user’s visit to a Web site.

Ad view (Online)

Actual viewing of an ad by the user. It is not directly measurable today, but inferred from the measurement of ads called for display on the user’s computer.

Address (Online)

Unique identifier for a computer or online site, usually a URL (Uniform Resource Locator) for a Web site or an e-mail address.


Ability of a service provider to signal from the headend or hub to a specified subscriber. The addressable functions include the ability to change a subscriber's level of service for premium channels, PPV, etc.

Addressable On-Screen Display (OSD)

Image superimposed on a screen picture that provides specific information about the display, such as channel number, channel logo or time of transmission.


Advertising expenditure.


A commercial time period that is scheduled immediately preceding or following a scheduled programme on the same station in which a TV commercial spot can be placed. Opposite of an in-programme placement. Also called a break position.

ADSL (Asymmetrical digital subscriber line)

A variant of DSL, ADSL is a data communication technology that enables faster data transmission over copper telephone lines than a conventional voiceband modem can provide. It does this using frequencies that are not used by a voice telephone call.


Company or other organisation purchasing commercial airtime on television for promotional purposes.

Advertising agency

An organisation acting as an agent for a producer of goods or services (an advertiser) devoted to developing and placing advertising in order to further the acceptance of a brand product, service or idea.

Advertising clutter

Volume of advertising to which viewers are exposed. In the case of television, advertising clutter may refer to the volume of advertising spots carried by a broadcast channel. Or, it may refer to the average amount of time (typically minutes per hour) during the day/daypart in which viewers are exposed to advertising spots. (see also Promotional Clutter)

Advertising spot

A unit interval (e.g. 10-second, 15-second, 20-second, 30-second, etc.) containing a commercial message supplied by an advertiser for insertion in the transmissions of a TV channel.

Aerial reception

Reception of off-air terrestrial transmissions by means of a collective aerial (MATV) or an individual household aerial that may be located (a) externally (e.g. on the roof), (b) internally and attached to the TV set or (c) internally and built in to the TV set. In some countries with large commercial MATV networks, MATV may be included under cable reception.


A notarised statement from a broadcast station that confirms the commercial actually ran at the time shown on the station's invoice.


A regional/local TV broadcast station bound by a contractual relationship with one or more networks to carry an agreed quantity of network-originated programmes and commercial announcements in parts of the schedule allocated for network programming.


A conversion figure between the base audience rating and the target audience rating. E.g. An index of 126 for target audience Adults 15-34 against a base audience of Adults 15+ means 15-34s obtained a 26% higher rating than the base average across all Adults 15+.

AFP (Advertiser funded programming)

(see also ASTV (Advertiser supported television))

AGF (Germany)

Arbeitsgemeinschaft Fernsehforschung: Group of four (formerly six) TV station families underwriting TAM contract in Germany. AGF includes joint industry representation on the board and in the supervising committees.

Aggregated viewing data

Processed viewing data that have been converted into total viewing estimates (e.g. programme, commercial break, advertising spot, second-by-second, minute, 5-minute and quarter-hour etc.) and no longer contain information about specific individuals/panel homes (i.e. cannot be used for direct calculations of reach/frequency).

Airing cost

The cost to air/broadcast a programme.

Airing date

The date of programme to be aired/broadcasted.


Computational procedure that usually involves a number of steps. For example, the "Algorithm for calculating ratings" is simply the set of sequential steps of computation for calculating ratings from the "raw" viewing data.

AM (Amplitude modulation)

The transmission of audiovisual signals in which the amplitude of a transmitting wave is modulated as a function of its intensity.

AMOL (Automated measurement of line-ups)

Term used in the USA to refer to unique programme codes. (see also Embedded Signal)

Amount of viewing (daily/weekly average)

Total amount of live or consolidated viewing across all channels/other sources included under total viewing.


General term for all radio frequency wave signals in the form of continuously variable quantities. Analogue signal information is superimposed on a modulated carrier wave (unlike digital signals which are made up of discrete pulses). Analogue TV channels have two carrier waves: one for audio (FM) and one for video (AM).


Another term for Advertising spot or Commercial. (see also Advertising spot)


A structure or devise used to receiving or transmitting electromagnetic waves.

AOR (Agency-of-record)

An advertising or media buying agency belonging to a group of agencies serving the same advertiser that has a privileged status in terms of being awarded special contracts or assignments that cover the group (e.g. media buyer negotiating commercial airtime deals with TV stations on behalf of all agencies within the group, who may have a restricted role in supplying the advertiser with supporting media planning services only).

API (Application programming interface)

Set-top box interface that enables the display of EPG's and other interactive applications on the TV screen.

AQH (Average quarter hour) ratings

Term used by some data suppliers that denotes the average audience across quarter-hour unit intervals.

ARF (Canada / USA)

Advertising Research Foundation: National trade association for advertising research in Canada and in the USA.


Arianna is the television ratings analysis tool of AGB Nielsen Media Research, helping broadcast researchers, agency planner/buyers and managers around the world navigate the complexities of TV ratings data within a single software environment. Arianna has been developed by AGB Nielsen Media Research, based on more than a decade of experience as a provider of proprietary television ratings analysis software. Expert understanding of, and experience in TAM, ensures comprehensive delivery of support to thousands of global users across 5 continents, in more than 30 countries.

ARPU (Average Revenue per User)

Measure of customer revenues generated by rental and other pay services in a given period (e.g. annual, quarterly or monthly). Widely used for telephony and Internet applications, ARPU is also a standard measure employed by pay-TV services, covering channel and other (e.g. equipment, betting, etc.) subscriptions, PPV and paid for on-demand services.

ASO (Analogue switch-off)

Mainly used in connection with terrestrial broadcasting, analogue switch-off denotes the cessation of analogue broadcasts, to be replaced by digital broadcasts. In Europe a number of governments have set target analogue switch-off dates between 2008 and 2012. (see also Digital Switchover (DSO))

Aspect ratio

Ratio of width of TV picture to its height regardless of the size of the TV screen. Most conventional TV channels employ a 4:3 aspect ratio, but all HDTV, some DTV and some SDTV services employ a larger (typically 16:9) aspect ratio.

ASR (Automatic spot recognition)

A proprietary solution for the automatic recognition of spots integrated in the AGB Nielsen Media Research TV Events system. The ASR engine scans real time the emissions digitalised from the Grabbers and stores the results in a database of recognitions. ASR works with both video and audio proprietary algorithms, to maximise the level of recognition.


The AGB Nielsen Media Research TV Events interface to insert the automatically recognised spots into the TV Events database.

ASTRA (Australia)

Australian Subscription Television and Radio Association: Industry body representing the interests of its members by providing a unified voice on issues affecting subscription television. ASTRA represents satellite services, narrowcast television services, programme channel providers, subscription television operators, communications companies and other associate members.

ASTV (Advertiser supported television)

US term for original TV programming that is syndicated to supported independent TV stations for a reduced or zero fee on the television back of financial support from one or more advertisers, in return for which the advertisers are granted commercial space within the programmes offered to the TV stations. The principle is similar to programme barter.

ATS (Average time spent viewing)

Total sum of all recorded time spent viewing (e.g. minutes) across a given period (e.g. day, week) divided by the number of individuals in the universe/population being measured. More commonly known as ATV. (see also ATV (Average time viewed))


The decrease in amplitude of a signal between any two points in a circuit. Usually expressed in decibels. Attenuation is the opposite of amplification.

ATV (Advanced television)

Term used by FCC (Federal Communications Commission) in the USA for digital television (DTV). (see also DTV (Digital television))

ATV (Average time viewed)

Average of the total minutes viewed divided by the total individual universe.

ATVLI (Indonesia)

Asosiasi TeleVisi Lokal Indonesia: An association whose members are Local TV stations in Indonesia.

ATVSI (Indonesia)

Asosiasi TeleVisi Swasta Indonesia: An association whose members are Privately Owned TV stations in Indonesia.

Audience accumulation

Reach measure denoting the total number of different people (or homes) exposed to a medium over a specified period; such as a half-hour TV programme broadcast.

Audience appreciation (AA) data

Supplementary data collected by some TAM systems that quantify viewer appreciation of programmes on a simple scale (e.g. from 1 = very poor to 10 = very good). TAM systems that produce AA data nearly always collect them from the installed panel sample via the meters, although they could also collect them from independent survey samples using other methods.

Audience composition

The profile of measured audiences to a channel, programme, etc. with respect to selected demographic and/or other variables.

Audience factor

A scaling factor used in the UK, to estimate some audience sizes when only homes and population data are available.

Audience share

Percentage of total TV viewing across a specified time interval of a given channel, programme or other use of TV set.

Audience turnover

The ratio of the cumulative audience to the average audience across a given period (e.g. programme, daypart).


Relating to sound or its reproduction; used in the transmission or reception of sound.

Audio comparison method

Technique of signal identification in which the meter collects sample audio data from images displayed on the TV screen, which it matches against an array of known signals from a central reference source in order to establish the identity of the measured signals.

Audio description

Spoken commentary for the benefit of visually impaired viewers that describes what is taking place on screen.

Audio matching

(see also Audio comparison method)

Auditel (Italy)

Joint industry committee responsible for TAM data supply in Italy.

Auditor (TAM)

Individual or company who evaluates the TAM system and its data quality.


Availability of a commercial position/time slot in a scheduled commercial break on a given TV channel/network that is available for purchase by an advertiser.

Average audience

The average number of members of a specified population (e.g. target group of individuals or households) viewing a TV channel over a given interval (e.g. programme, daypart).

Average minutes per person (Avg Min/Pn)

The average minutes viewed per person belonging to a specified target universe/population across a selected time period. (see also ATS (Average time spent viewing))

Average minutes per viewer (Avg Min/Vw)

The average minutes viewed per person belonging to a specified target universe/population across a time interval, calculated against only those who viewed at all during that period. In contrast to average minutes per viewer, this measure covers all members of the population; i.e. viewers and non-viewers alike.

AVI (Audio video interleave)

Multimedia container format introduced by Microsoft in November 1992 as part of the Video for Windows technology. AVI files contain both audio and video data in a standard container that allows simultaneous playback.


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B2B (Business to Business)

Business to business service.

Back channel

A return communications pathway between users and content providers, such as an Internet connection using a modem.


(1) Backbone telecommunications pathways used for transporting traffic from central site(s) to distribution sites (viz. local exchanges) to end users, and vice versa. (2) One-to-one uplink feeds to satellite for sending broadcast TV signals to the studio.

Bandwidth/ Bandwidth capacity

Measure of transmission capacity that specifies the complete frequency range over which a circuit, transmission channel, or electronic system is allocated to function. Transmission channels requiring large capacity, such as digital TV channels with high picture quality, are sometimes described as "bandwidth hungry". Bandwidth may also refer to maximum channel throughput for different types of connection (measured in kbit/s or Mbit/s).

Banner (advertisement)

A graphical Internet advertising unit, often including links to another page or website selected by the advertiser, which the user accesses by clicking on the ad.

BARB (United Kingdom)

Broadcasters' Audience Research Board: Joint industry committee responsible for TAM data supply in the United Kingdom.

Base unit

Meter installed on all TV sets within the home, generating statements of what source is being tuned to when the TV set is on, and which persons in the home have registered their presence as viewers. (see also Slave Meter)

Basic cable

Collective term for TV and radio channels featuring in the basic entry channel packages offered by cable operators to their customers for a low subscription charge. It excludes mini-pay TV channels on more advanced tiers as well as premium pay-TV channels and other services (e.g. PPV/paid for on demand services).

Baud rate

The measure of the speed of transmission of a digital code, as defined by the number of distinct symbol changes per second to a digital signal stream. Each Baud (Bd) may contain one or more bits of information. (see also Bitrate/Bit rate)

BBM Canada (Canada)

Non-profit making tripartite co-operative originally established by the Canadian Association of Broadcasters (CAB) and the Association of Canadian Advertisers (ACA). It conducts its own audience measurement surveys for television and radio. Organisation originally known as The Bureau of Broadcasting Measurement, changing its name to BBM Canada in 2001.

Behavioural targeting (Internet)

Marketing tool employed by online advertisers for improving the efficiency of their campaigns, which involves determining which ad messages to send to a user on the basis of information collected about the user’s past web browsing behaviour.

BER (Bit error rate)

The fraction of bits transmitted that are received incorrectly.

Beta test

Trial test of a software product or application in the field prior to its final release, aiming to verify that the product or application performs the functions it is supposed to in a real world environment.

Between programme break

Commercial break placed between two different programmes. Also known as End Break (EB).


Airtime awarded to a programme sponsor at the beginning/end of a sponsored programme or at the beginning/end of commercial breaks within the programme for showing the sponsor credits. Also known as Break Bumper or Sponsorship Bumper in the UK.


Elementary unit of information/data stored as a choice between two mutually exclusive possibilities, such as 1 or 0 in binary notation.

Bitrate/Bit rate

Transmission speed expressed as the number of bits per second (b/s or bps), but more often expressed as multiples (e.g. 1 kbps = 1,000 bps; 1 Mbps = 1,000,000 bps; 1 Gbps = 1,000,000,000 bps). Bitrates denote the amount of information that can be transferred in a given time interval. Video applications are highly bitrate intensive. The required bitrates depend on a number of factors, such as desired picture quality, sampling rate of original material, compression algorithms, method of encoding, amount of information contained in the samples (e.g. very high for sports, lower for studio interviews). Typical present day requirements are 1Mbps for VHS, 5 Mbps for DVD and 15 Mbps for HDTV.


P2P file-sharing protocol that allows for the distribution of a wide range of content by reducing the dependency of recipients on the originator and without the originator having to incur the entire costs of hardware, storage and bandwidth use.

Blog (Blogging)

Web site on which Internet users make regular entries. Most blogs are based around a particular theme, with readers encouraged to add comments. Blogs typically contain a number of pages of related topics, along with links to other blogs and web sites. Forms include text, video (vblog), photographs (photoblog), or audio (podcasting). Authors of blog sites are known as bloggers.


Wireless standard and communications protocol for short-range connections and exchanges of information between devices such as PCs, PDAs, mobile phones, printers, headset, video game consoles, etc., using a secure, globally unlicensed short-range radio frequency.

Blu-ray Disc

Ultra-high-density optical disc format for the storage of digital media, including high-definition video. Sony’s Blu-ray Disc has emerged as the accepted global standard after a lengthy battle with Toshiba’s HD DVD format.

Body programme

Programme content only, without commercial break.


French term referring to the selection of general and thematic TV channels that are offered as a package to subscribing households.

BPS (Indonesia)

Biro Pusat Statistik: Indonesian Government’s official statistical organisation.


(see also Commercial Break)

Break position

Position of a commercial spot within a break; e.g. first in break/last in break.


Any wired or wireless transmission pathway with high bandwidth capacity. Term is widely used to denote systems that are able to relay large numbers of video channels and other electronic services, including Internet access, and provide return pathways that permit subscribers two-way communications and interactivity.

Broadband cable

Cable networks with high bandwidth capacity for delivering multiple TV channels and other electronic interactive services, such as cable telephony and Internet access.

Broadband services

Term widely used to denote on-screen two-way interactive services offered by broadband systems, such as e-mail and Internet access.


Over-the-air transmission of TV channel programming from a central broadcast source to multiple homes in the channel reception area via a network of land transmitters or via satellite.

Broadcast coverage area

Geographic reception area within which a broadcast TV channel can be received according to set technical criteria of signal quality. The broadcast coverage area is also referred to as the technical reach of the broadcast TV channel.


Company/organisation broadcasting one or more TV channels.


Over-the-air distribution of audio and/or video signals (programmes) to a large number of recipients ("listeners" or "viewers") within the technical reach of the signals. The main types of broadcast transmission include satellite, terrestrial and MMDS distribution.


Buffer is a generic term for computer memory storage. Among the uses of the term, buffering refers to the advance storage and queuing of transmitted video content over wired systems before its display on screen in order to preserve picture quality when there is variable bandwidth capacity and the quality of service (QoS) cannot be guaranteed at any given moment.

Bumper in/bumper out

A term used for a short duration advertisement (usually 5 second) that is placed before a programme begins (bumper in) and after the programme ends (bumper out).


The offer of several products as a single product or package (e.g. in the marketing of triple play offers involving broadband, telephony and television). Bundling can assume many forms in relation to the design and marketing of pay-TV packages.

Burn a CD/DVD

Act of recording audiovisual content on a CD or DVD.


Period of concentrated activity in an advertising campaign, usually lasting several weeks, that is aimed at achieving high frequency and awareness at the time of the campaign and in the period immediately afterwards.


Basic data unit, comprising groups of 8 data bits that are processed together.


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CAANZ (New Zealand)

Communication Agencies Association of New Zealand (

Cable franchise area

Geographic area in which a cable operator has been licensed to install a cable system.

Cable modem

A data modem that uses the bandwidth of a cable system.

Cable network

(see also Cable television system)

Cable operator

Company/organisation running a cable network.

Cable reception

Reception of television transmissions, from whatever originating source (i.e. whether terrestrial, satellite or cable) by a wired cable television (CATV) system serviced by a cable operator. TAM systems may sometimes classify MATV and/or SMATV as cable reception depending on local market structural distinctions that are found to be most relevant.

Cable television system

Wired transmission system serviced by a cable operator, who receives television transmissions centrally and relays them to subscribers via a cable headend across a cable network.

CAM (Conditional access module)

Electronic hardware facility, usually incorporating a smart card slot, that makes it possible for a set-top box or other equipment to display encrypted, conditional access content.


A promotional effort over a specified interval based on the same strategy and creative idea. TV advertising campaigns typically consist of a schedule of advertising spots that are transmitted in one or more discrete batches lasting several weeks or longer or at lower intensity over longer and more continuous periods. (see also Burst, Drip)

Campaign planning software

Predictive software used by media planners to estimate the audience for a schedule of advertising spots.

CAPI (Computer assisted personal interview)

Method of conducting face-to-face interviews with the use of a personal computer for prompting questions and recording answers.

Carriage fee

Small monthly fee per subscriber, which is normally paid by pay-TV service providers/platform operators to the channels they carry, although the reverse can also apply depending on available capacity, channel demand and conditions of service pricing, which vary greatly from country to country.

Cash discount

A discount granted by the media supplier to an advertiser for payment within a certain period of time - e.g., a 2 percent discount if payment is made within ten days of invoice. Also referred to as prompt payment discount.

Catch-up TV

TV service that makes broadcast programming available on-demand for a specified period after the real-time broadcast (e.g. 7-day catch-up TV).

CATI (Computer assisted telephone interview )

Method of conducting interviews over the telephone with the use of a personal computer for prompting questions and recording answers.

CATV (Community antenna TV)

Another term for cable television system or cable network. Key defining criteria are that the CATV system must relay cable transmissions to multiple dwellings on multiple premises and is serviced by a cable operator who charges a monthly per subscriber fee.

CATV (Conditional access TV)

Security technology used by pay TV operators to ensure that only authorised subscribers are able to access their content. Conditional access involves encrypting the transmissions and providing programmable regulation of their decryption , typically via smart cards.

CAWI (Computer assisted web interview)

Similar piece of software as CAPI/CATI but as a Web-authoring version. Respondents can answer the questions either at home or in their workplace, even with several interruptions. . (see also CAPI (Computer assisted personal interview), CATI (Computer assisted telephone interview))

CB (Centre break)

(see also Within programme break)

Cbb (Closing break bumper)

(see also Obb (Opening break bumper))

CDN (Content delivery network)

Network of computers acting in co-operation in order to deliver content to end users over the Internet.

Cell panel control

Panel control consisting of two or more interlocking variables.

Cell-matrix panel control

Panel control consisting of two or more interlocking panel variables.

Cell-matrix weighting

Method of weighting that employs a single matrix of interlocking variables for adjusting the actual sample profile to the target sample profile.

Cellular interface

Meter interface with cellular phone connection.


The process of collecting vital information on the social, economic and housing characteristics of every member of a population. In contrast to sampling where information is only obtained from a subset of a population.

Central processing base

Term sometimes used to refer to the central data collection, storage and processing system at the offices of the data supplier.

Chain break

The time between network programmes when a network affiliated station identifies itself to viewers and during which commercial announcements are aired. (see also Commercial Break)

Channel coverage

Number of individuals/TV homes that can receive a TV channel within its broadcast coverage and/or other (e.g. cable, DSL network) distribution area, as defined by set technical reception criteria. Channel coverage is often expressed as a percentage of the total survey population. (see also Broadcast coverage area)

Channel frequency map

List of TV channels/other signal sources and their associated frequencies that are found and recorded for each monitored TV set in the home during an exhaustive tuning check by the panel technicians and later used to identify signal transmission sources in meter systems that measure frequencies.

Channel mapping

A feature of some TV sets, VCR's and set-top boxes which allows them to receive the transmissions of a TV channel in the same tuning position even if it has moved to a different frequency.

Channel penetration

Estimated percentage of TV homes within the survey universe that (a) can receive and (b) have one or more of their TV sets tuned to a given TV channel. The definition may include stipulations about acceptable picture quality.

Channel reception

TV channels that can be received by a given TV set or TV home, as determined by an exhaustive check of tuning frequencies.

Channel share

Estimated audience share of a TV channel. (see also Audience share)

Channel tuning/ viewing via satellite receiver

Selection of satellite TV channels via the tuner belonging to the satellite receiver.

Channel tuning/ viewing via VCR

Selection of TV channels during viewing by means of the VCR tuner.

Channel viewing repertoire

Average number of channels that viewers within a selected population (e.g. satellite TV homes, multichannel TV homes, etc.) watch at least once during a specified interval (e.g. day, week, month).


The standard method of scheduling programmes in prime time by offering different programmes in the same time period every night. This is the opposite of "strip" programming, in which the same series airs different episodes in the same time period every day. Strip programme scheduling is the prevailing form for all other dayparts except prime time.

Churn (rate)

Index of turnover applied to commercial pay-TV systems as a whole or to channel packages, especially premium pay-TV services. It is an important indicator of pay-TV service performance, which may be defined in several ways. The usual method of estimating churn is to divide the number of subscriber disconnections during a set period by the average number of subscribers during that period or the number of subscribers at the beginning of that period. This produces a result representing an annualised percentage.

CI (Completed interview)

Interview with eligible survey respondent that has been successfully completed and validated.

CIM (Belgium)

Centrum voor Informatie over de Media/Centre d'Information sur les Médias: Non-profit-making joint industry committee overseeing circulation audits for press, Internet sites and outdoor posters as well as being responsible for all audience measurement to do with the display advertising media.

Claimed weight of viewing

Panel classification variable based on separate establishment survey data that record claimed weight of household viewing. Some TAM systems use claimed weight of viewing for a panel control as a precaution against sample bias due to differential acceptance/installation rates amongst heavier and lighter viewing households.


AGB Nielsen Media Research's TV Events quality control procedures to ensure top quality programme, break and spot database.

Click fraud

Form of Internet crime, where a person, automated script or computer programme clicks on an Internet advertisement in order to generate a charge-per-click.

Client initiated ad impression

(see also Ad impression (Online))


A brief segment excerpted from a broadcast stream. In AGB Nielsen Media Research's TV Events the term usually refers to the commercial spot stored in a separate video file.


Grouping several commercials together during one break.

Coaxial cable

Transmission technology used by broadband data and cable systems that consist of transmitting electrical signals down conducting wires with protective insulation.

Co-channel interference

Interference on a channel due to another signal on the same channel.


A codec (Coder-Decoder) is a piece of hardware or software for encoding and decoding digital audio and video signals.


Device for converting a signal from one form into another (digital form), to meet the requirements of a particular form of communication.


Advertisement, announcement, spot or message aired on television, radio or cable which is paid for by an advertiser.

Commercial airtime quota

Airtime minutage allowance that is available for advertising according to international and national rules that vary greatly across different countries. The rules may also vary for different types of TV stations within the same country. For example, public service stations that receive mixed public and advertising funding may be subject to stricter quotas than other channels. Likewise, licensed terrestrial commercial analogue services are often subject to more stringent quotas than other cable and satellite channels as a condition of their licences. Lastly the rules will often additionally specify the distribution of commercial minutage by time of day, the frequency and positioning of commercial breaks within and between programmes, the duration of commercial breaks and other requirements, such as the obligation on some TV channels to sell all their airtime in order to limit TV channel manipulation of advertising demand and consequent airtime prices.

Commercial and programme logs

Record of all commercials and programmes transmitted by TV channels. The information may be provided by the TV channel itself or by an independent source and is matched against processed individual viewing statements so as to permit viewing figures for specific commercials and programmes. The logs may contain additional information, such as programme genre codes, which can be used to estimate and report audiences for different kinds of programming.

Commercial break

An interval during which advertisements are shown within television transmissions.

Commercial impact

(see also Impact)

Commercial ratings

Audiences for advertising commercial spots. Different TAM systems employ different algorithms for computing commercial ratings/GRPs for minute by minute or second by second GRP measures. (see also GRP (Gross rating point))

Commercial TV

Profit-making TV channels/services that rely on commercial advertising, pay-TV or other (e.g. telephone voting) payment revenues from their audiences.

Common interface

Hardware and software interface that may be embedded in TV sets or set-top boxes to permit the addition of other components, such as conditional access modules for pay-TV applications, for enhancing the functionality of the TV set.

Community television

Television services owned and operated by "communities" rather than governments, business or television industry professionals. They may be funded through government grants or subsidies, sponsorship, membership, or a combination thereof.

Competition mapping

A mapping of the performances of competing TV stations.

Compression/Data compression

Encoding technology for improving the transmission rates and/or decreasing the bandwidth requirements of digital TV services that entails reducing the digital data files (i.e. reducing the number of bits) through removing redundant information, thereby enabling multiplex operators to squeeze more channels on to a single carrier frequency that would have originally carried just one analogue TV channel. Present day more advanced compression (e.g. MPEG-4) and other broadcast transmission technologies are making it possible for single carrier frequencies to carry ten or more digital TV channels; although digital terrestrial broadcast systems typically carry six to eight digital channels per carrier frequency.

Computer bureaux

(see also Software house)

Concentration index

A number indicating a percentage difference between one value and a benchmark value for comparison. The benchmark value, however defined, is fixed at 100. Accordingly, an index of 110 indicates a positive absolute difference to the benchmark value of 10 percentage points (or 10% relative difference); whilst an index of 90 indicates a negative absolute difference of 10 percentage points (or a -11% relative difference).

Concurrent viewing

Same individual registered by a TAM meter as a viewer for two or more TV sets at the same time.

Conditional access

(see also CATV (Conditional access TV))

Conditional buy-through

Common form of pay-TV pricing where the purchase of premium content is conditional on buying one or more other services. The most common example is the requirement by many pay-TV operators to buy a basic subscription package in order to be able to subscribe to a film or sports package.

Confidence interval

Term used in parametric statistics to specify the margin of error associated with a particular survey estimate for a given level of significance. For example, 95% confidence interval denotes the range of values surrounding the survey estimate within which there is a 95% probability that the true population value will lie. Depending on the level of certainty required, higher or lower probability values may be used to specify the confidence interval.

Confidence limits

The lower and upper boundaries/values of a confidence interval, that is, the values which define the range of a confidence interval.


Widely employed general term for designating the interoperability and ability of TV, PC and other video/audio equipment to communicate with one another in the home or over a network (e.g. P2P file sharing). (see also File-sharing)

Consolidated audience

The consolidated audience is the sum of the live and timeshift audiences.

Consolidated viewing

Sum of live and all timeshift viewing of television transmissions within a set time interval after the transmissions (Note: definition allows for the same viewer to be counted more than once as a viewer of a transmission).

Constant viewing

Long viewing session without any change in registered set use or viewer presence. Constant viewing is used by some TAM systems as a quality control during data validation.

Consumer generated media

Materials posted by users on the Internet. At first, the term was mainly used in connection with Internet forums, blogging sites and wikis; but has subsequently widened to cover new multimedia, video and social networking applications.

Content aggregator

Company or organisation that gathers material for distribution to end users after acquiring the necessary rights.

Content protection

General term for protection of copyright, whether via conditional access and encryption of broadcast signals or DRM measures relating to digital networks.

Content provider/supplier

Company or organisation responsible for creating content, whether movies, TV programming or interactive games applications, etc.

Contention ratio

Ratio of the potential maximum demand to the bandwidth available on a network. The greater the number of users, the higher the ratio. During periods of peak demand this can result in lower effective bandwidth. In the case of on-demand TV services, the contention ratio is the ratio of total subscribers to the peak number of unique simultaneous streams.

Contract period

Period of data purchase/delivery as agreed between the data supplier and its clients. Formal JIC or MOC industry contracts typically run from five to ten years, with extension options included.

Contract specification

Technical terms of survey content, data delivery and terms of purchase as laid down in TAM contracts between data suppliers and their clients.

Contracting party(s)

Parties such as JIC, MOC and TRCC organisations that contract TAM services from one or more data suppliers.


Data supplier contracted by an industry body/organisation to supply TAM data as specified by the contract.


The delivery of several types of content (e.g. TV broadcasts, Web TV, hi-fi audio, etc.) to a single receiver and output source. The introduction of digital technology has greatly expanded the potential for convergent applications on the TV screen.

Conversion factor

An assumed scaling factor that may be used for converting a measure classified by one criterion (e.g. household rating) into a measure classified by a different criterion (e.g. Adults 25-44).


Device for changing the frequency of a signal. Converters are commonly used (a) by cable and other TV distribution systems that entail reception of incoming signals and retransmission to viewers on locally available frequencies as well as (b) for enabling reception of digital TV signals on analogue TV sets. (see also Decoder)


Information sent by a server to a web browser and sent back by the browser unchanged each time it accesses the server. The only modification is that the cookies can store information about the user’s navigation of the Web site. Originally developed in order to assist shopping basket applications, cookies can serve in a number of contexts to authenticate, track and store information about visitors to a Web site. This has led to concerns about privacy. Advertising companies may use cookies to track user behaviour over multiple Web sites, which can be used for behavioural targeting. (see also Behavioural targeting (Internet).)

Cost efficiency

Financial performance measure of a schedule of advertising spots that is calculated by dividing the price paid by the audience delivery with reference to the target audience(s) of the advertising campaign. The principal measures of cost efficiency are Cost per rating point (CPR) and Cost per thousand (CPT or CPM).

Couch potato

Television viewers who just sit relaxed and watch TV, doing little to interact with the TV set beyond changing channels when the mood takes them.


Measure of advertising reach. Derivative terms like 1+ cover and 4+ cover denote the percentage of the target audience that has been exposed to a schedule of advertising spots at least a certain number of times (e.g. at least once, at least four times, etc). (see also Reach)

Coverage area rating

The estimated audience size of a TV channel/programme within its coverage area, expressed as a percentage of the total potential audience.

Coverage/Coverage area

Number of individuals/homes that can receive or are exposed to a medium. (see also Channel coverage)


Defines the condition where members of a reference target are the focus of an analysis only if they are watching TV together with other members, chosen according specific demographics. An example of a Co-viewing target is Females watching with Children.

CP (Campaign period) (advertising)

Interval spanning from the first to the last days of a campaign schedule of advertising spots.

CPA (Cost-per-action)

Cost of Internet advertising based on the number of visitors taking some specifically defined action in response to an ad, divided by the money paid.

CPC (Cost-per-click)

Cost of Internet advertising based on the number of clicks an ad receives divided by the money being paid. CPC’s vary according to the search engine being used.

CPE (Consumer premises equipment)

Equipment that subscribers to a service must install in their homes in order to receive it (e.g. set-top Box with PVR functionality, wireless router, etc.).

CPI (Cost-per-impression)

Cost of Internet advertising based on the number of ad impressions divided by the money paid.

CPP/CPRP (Cost per Rating Point)

The average cost of achieving one commercial rating point (i.e. advertising GRP) with a 30 second advertising spot (or other standard unit of airtime) for a given target audience. CPP's are widely used as a measure of the cost efficiency of advertising campaigns or for comparing price differences across different TV stations. The alternative widely used measure of cost efficiency is Cost per thousand (CPT or CPM).

CPT/CPM (Cost per thousand/Cost per mille)

(1) Television: The average cost of achieving 1,000 commercial impacts against a specified target audience, and usually adjusted to a 30 second advertising spot length. CPTs/CPMs are widely used as a measure of the cost efficiency of advertising campaigns or for comparing price differences across different TV stations. The alternative widely used measure of cost efficiency is advertising Cost per rating point (CPR or CPRP). (2) Internet: Cost of achieving 1,000 ad impressions.

Criterion of viewing

Instruction to survey respondent on when to record himself/herself as a viewer. In peoplemeter measurement, this equates with the instructions of when panel members or their guests should register their presence as viewers (e.g. "In the room with TV set on and watching", or "in the room with TV set on", etc.).

Cross-border overspill

Overspill of domestic TV station signals into neighbouring countries.

Cross-sectional data analysis

Analysis of aggregated data, that is based on sample estimates of audience size/volume and composition per unit time interval. Key output measures are audience ratings, amount of viewing and audience share.

CRT (Cathode ray tube)

Traditional technology for displaying TV images on a screen by means of an electron gun firing electrons at a fluorescent screen. Though successful throughout the last century, CRT is being rapidly superseded by other technologies that can generate images on much larger flat screens, avoiding all the bulkiness of CRT boxes. (see also Large-screen television technology)

CSS (Content scramble system)

DRM scheme used on some DVDs. (see also DRM (Digital rights management))

CSV (Coincidental study of viewing)

Parallel surveys of viewing for checking the accuracy of the main survey. CSV's are either "internal", based on the same sample as the main survey, or "external", being based on a separate independent sample. External CSV's are rarely used in TAM research, but most peoplemeter panels employ internal CSV's (usually once or twice a year) as a systematic quality control for checking (a) the accuracy of key panel classification variables that are liable to change (e.g. household size, number of TV sets) and (b) the accuracy of viewer registration through comparing the CSV claims with contemporary meter records.

CTR (Click-through rate)

Unit measure of online advertising defined as the number of clicks on an ad on a web page divided by the total number of times the ad was delivered (ad impressions). An alternative definition sometimes used is to define CTR as the number of users that click on a web page divided by the total number of times the ad was delivered.

CTS (Content tracking system)

Content identification technology based on comparison of audio signatures used for a variety of TAM applications. Its principle of operation includes generating signatures from the unknown content's audio track and comparing those signatures against identical signatures generated for all measured content streams (e.g. "TV channels").

Cume (Cumulative) rating

Cumulative total of ratings across a target audience over a given period, such as an advertising campaign, or fixed time interval (e.g. week month).


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DAB (Digital audio broadcasting)

International transmission technical standard for digital radio services.

Daily reporting sample

(see also Net daily reporting sample (in-tab sample))

Data accessibility

Degree to which client users can access data generated by a TAM system. Different users may enjoy different levels of access. The degree of access is partly a function of the data which Users are permitted to examine and partly a function of the software options for analysis.

Data availability

Availability of TAM data to different interest groups: not just the primary users comprising advertisers, media buyers and media owners, but also secondary users comprising software houses/computer bureaus, market research companies, trade press and other potential interest groups.

Data compression

A process that reduces the number of bits used to encode a signal by eliminating gaps, empty fields, redundancies, or unnecessary data. (see also Compression/Data compression)

Data entry

Entering data into computer, which includes keyboard entry, scanning and voice recognition. In relation to AGB Nielsen Media Research's TV Events, it is the user interface module for entering detailed broadcast information into the database stored on the TelePad Server.

Data fusion

Market research output that combines data from two separate, though not necessarily independently drawn, survey samples by means of pairing individuals from each contributing sample on the basis of socio-demographic and/or other data. It may be used as an alternative to single source survey research in order not to over-burden survey respondents with the collection of two sets of research data.

Data reporting threshold

Threshold of acceptable sample size for permitting data access. There are wide variations in practice across different TAM systems. Within Europe, about half the TAM systems employ thresholds for warning users when sample sizes for analysis are low and consequently unstable. Slightly fewer employ blocking thresholds that prevent access when sample sizes are considered unacceptably low for analysis.

Data supplier

Market research company engaged in the collection and production of TAM data for delivery to the market.


Broadcasting of information and other data services via digital TV, often as a supplementary offering to enhance the appeal of digital TV channels.

Day after recall

Method of collecting audience data in interview surveys or self-completion questionnaires that ask respondents to recall their viewing or other activities on the previous days. Surveys may employ a recall period of more than one day (e.g. two-day recall or up to seven-day recall), or they may use past 24 hour recall as an alternative to day after recall.


Division of the broadcast day constituting a single timeband (e.g. early morning: 06.00-09.00; peak or prime time: 19.00-23.00, etc.). Most TAM systems divide the day into about eight dayparts (e.g. Early morning; Mid to late morning; Lunchtime; Early to mid afternoon; Late afternoon; Peak/Prime time, Late evening; Night). The dayparts correspond with broad variations in audience size and composition across the broadcast day.

DB (Delayed broadcast)

A network TV programme that is delayed for airing in a given market at a different time than the time it airs nationally.

DBS (Direct broadcasting by satellite)

Hangover term coined during the eighties to refer to WARC (World Administrative Radio Conference) international provisions for direct broadcasting by satellite. The WARC plan envisaged allocating each country five K band frequencies for high power analogue satellite transmissions that would permit nationwide reception with dishes no greater than 90 cm in diameter. Several national projects were developed during the early eighties; however, the DBS projects were rapidly superseded by major technological advances that created room for a far greater number of TV channels to be broadcasted by medium power satellites using a different part of the radio frequency spectrum and at much lower costs.

DCT (Digital cable TV)

Digital television services transmitted via cable.


Device (also called Converter) that decodes digital transmission signals and converts them for display on to the TV set.

Decoder interface

Interface between a meter and a set-top decoder that permits the monitoring of signals passing through the decoder.

Definitive viewing (data)

Final complete set of viewing statements from which quantitative estimates of viewing are generated.


The elapsed time between the instant when user information is submitted to the network and when it is received by the user at the other end.

Demographic variable

Population variable for classifying individuals or households in terms of personal or family characteristics. Examples include Region; Type of settlement; Household size; Age; Sex; Social grade/Socio-economic level; Work status; Occupation; Education; Presence of children; Life stage.


An electronic circuit that restores a scrambled video signal to its standard form.

DFM (Direct frequency measurement)

TAM methodology that identifies channels through metering their frequencies and comparing their records against the channel map for the TV set or other input source being monitored.


Method of Internet access that involves hooking up the PC to a telephone network using a modem and telephone line. Also known as narrowband. Dial-up was the early form of Internet access and is significantly slower than broadband, which is now superseding it.

Diary measurement

Family of TAM methodologies in which survey respondents record their viewing in diaries. Diary samples may be discrete or they may constitute short or long term panels. TAM diaries normally consist of booklets with one page, or a double-page spread, for each day of the week. There is considerable scope for variation in terms of format, unit intervals of measurement (e.g. quarter hour/five minute), criteria of viewing selection of sample (i.e. household or individual), instructions on when to fill in and methods of administration and collection. National diary TAM systems have given way to national peoplemeter TAM systems in most countries, but diaries are still commonly used in larger countries for regional/local audience measurement or for collecting data from rural areas.


General term for all radio frequency wave signals that have been transformed into binary units of data (bits). The transformation of all video and audio signal information into bits is fundamental to expanding the opportunities for multimedia and convergent applications sharing the same output source (i.e. TV or PC screen).

Digital audio player

Device for playing, storing and organising digital music files.

Digital compression

(see also Compression/Data compression)

Digital set-top box

A device which accepts digital encoded television broadcasts and converts them to display on an analogue television set. New boxes with added functionality provide local storage of programming on hard discs, and Internet access.

Digital switchover (DSO)

Process of replacing analogue with digital TV broadcasts, for which prior analogue switch-off is a prerequisite condition.


Process of converting an analogue signal into digital format.

Disaggregated viewing data

Same as Elementary or Respondent level viewing data - Processed viewing data held at the level of individual respondents. The basic components of disaggregated viewing data are individual viewing statements consisting of complete time records across each broadcasting day of all viewing sessions by every family member and guest on all metered TV sets in the home. (see also Individual viewing statements)

Dish antenna

A high-grain antenna, shaped like a dish, which is used for the transmission and reception of ultra-high-frequency and microwave signals.

Disproportional sampling

Sampling in which different sub-populations have different probabilities of selection, resulting in over-sampling/under-sampling of some groups compared with others. Disproportional sampling by selected region(s) is quite common in TAM research.

Distribution platform

Operating system for distributing TV services to viewers. Distribution platforms are typically classified according to whether the signals are in analogue or digital and delivered to the viewer via satellite, cable, terrestrial, DSL, FTTH reception. Further distinctions may be made according to whether the services are free or pay, and whether packaged or delivered by a particular platform operator, which markets its TV services as a single entity.


Video codec created by DivX, Inc. (formerly DivXNetworks, Inc.), which has become popular due to its ability to compress lengthy video segments into small sizes while maintaining relatively high visual quality.

DLP (Digital light processing)

Rear-projection technology developed and owned by Texas Instruments for projecting video images on a large screen by means of a matrix of microscopically small mirrors on a semi-conductor chip. DLP currently competes with Plasma Display and LCD technologies fro large-screen HDTV. (see also Large-screen television)

DMB (Digital multimedia broadcasting)

Digital radio transmission system capable of operating in the VHF, UHF and L-Band frequency bands and based on the Eureka 147 DAB standard for sending multimedia (TV, radio and data) content to mobile devices, such as mobile phones. DMB services launched in South Korea in 2006, and shortly after in Germany, but since withdrawn.

DMCA (Digital millennium copyright act)

A US copyright law which criminalises production and dissemination of technology that can circumvent measures taken to protect copyright, not merely infringement of copyright itself, and heightens the penalties for copyright infringement on the Internet.

DNS (Domain name system)

Stores and associates many types of information with domain names, but most importantly, it translates domain names (computer hostnames) to IP addresses. It also lists mail exchange servers accepting e-mail for each domain. In providing a worldwide keyword-based redirection service, DNS is an essential component of contemporary Internet use.

Docking station

Recharging device into which participants in portable peoplemeter research place their meters overnight.

DOCSIS (Data over cable service interface specification)

An international standard developed by CableLabs that defines the interface requirements for cable modems involved in high-speed data distribution over cable television networks. The latest revised version, DOCSIS 3.0, released in August 2006, provides significantly faster upstream and downstream speeds than earlier versions and in excess of 100 Mbit/s.

DOG (Digital on-screen graphic)

Channel identification logo, usually appearing in top left or right corner of the screen.

Domestic TV channel

Any TV channel whose programmes and/or advertising are specifically targeted at national, regional or local audiences within the country of reception. The definition is independent of the point of origin of the broadcasts. At the same time the same TV channel may be broadcast as a domestic service to more than one national market.


Signal pathway from the satellite to the earth.


Reception of data from a remote system, such as a web site or FTP server and related systems. Upload is the exact opposite.


Term used widely in interactive TV (iTV terms) to refer to the signal pathway from the service provider (e.g. cable operator) to the home. This will usually have higher bandwidth demands than the upstream return path from the home to the service provider. Opposite of Upstream.


Continuous low intensity advertising over an extended period, usually aimed at giving regular reminders to viewers.

DRM (Digital rights management)

Sum of technologies employed by rights owners/content providers for authorising access and limiting use of content transmitted over a digital network in accordance with the copyright terms. DRM applies primarily to IPTV content. One of the key aims is to prevent unauthorised duplication of content and transmission to other parties via file sharing or portable storage items such as CDs.

Drop-down menu

On-screen text menu offered by interactive digital TV channels that viewers can call up with their remote control handsets.

DRTV (Direct response TV)

TV infomercials or advertising spots that permit or encourage consumers to directly respond to the advertiser.

DSL (Digital subscriber line)

Generic term for technologies that permit the delivery of broadband services over voice telephony networks.

DSLAM (Digital subscriber line access multiplexer)

Network device, usually located in the local exchange, for aggregating the data connections of multiple end-users. The DSLAM connects the customer's DSL with the core high-speed Internet backbone network.

DSP (Digital signal processing)

Study of the digital representation of signals, often involving the digitisation of analogue signals, which may subsequently be de-converted into analogue form for onscreen display. DSP may take place in a number of different domains, such as time, space and frequency. Applications include digital image processing and video compression.

DST (Daylight saving time)

Daylight saving time (also summer time in British English) is the convention of advancing clocks so that afternoons have more daylight and mornings have less. Typically clocks are adjusted forward one hour near the start of spring and are adjusted backward in autumn. Modern DST was first proposed in 1907 by William Willett. Many countries have used it since then; details vary by location and change occasionally.

DST (Digital satellite television)

Digital services transmitted via satellite and received directly by means of individual satellite dishes or via SMATV connections.

DTH (Direct-to-Home)

Direct-To-Home satellite transmission and reception - TV transmissions via satellite intended for "direct-to-home" reception in households equipped with parabolic dish antenna.

DTMB (Digital Terrestrial Multimedia Broadcast)

Digital terrestrial television standard applied in China. Also called DMB-T.

DTR (Digital television recorder)

Another term for PVR and DVR. (see also PVR (Personal video recorder))

DTT (Digital terrestrial)

Digital TV broadcasted terrestrially over the air for reception by television (DTT) aerial antennae.

DTV (Digital television)

General term for TV services that are transmitted into the home digitally, where they are received either by a set-top box decoder, which converts them into analogue form for display on a conventional analogue TV set, or by an integrated digital TV receiver.


Audience overlap across successive unit intervals of measurement.

DVB (Digital video broadcasting)

Collection of open standards for digital television maintained by the DVB Project. The family of DVB standards includes DVB-S, DVB-S2 DVB-SH and DVB-SMATV (satellite); DVB (cable); DVB-T, DVB-T2 (terrestrial); DVB-H (mobile handsets); as well as additional microwave distribution standards. DVB standards also cover conditional access (DVB-CA), software platforms for consumer video applications (DVB-MHP) and return channels. Each standard may exist in SD or HD formats. The DVB-T2 standard is not yet finalised, but awaits adoption and approval by ETSI, probably during 2008.

DVB project

Industrial consortium of 270 members for the development and promotion of DVB standards, as published by the Joint Technical Committee (JTC) comprising the European Telecommunications Standards Institute (ETSI), the European Committee for Electrotechnical Standardisation (ECES) and the European Broadcasting Union (EBU). DVB standards are widely used inside and outside Europe.

DVD (Digital versatile/video disc)

Disc containing audiovisual materials in video for display on the TV screen by means of a DVD player.

DVD (Digital video disc) player

Device for playing, but not recording digital video discs.

DVDR player

Device for playing and recording digital video discs.

DVR (Digital video recorder)

Devices that allow TV viewers to timeshift, pause and fast forward (until real time) using hard-drive video storage. (see also PVR (Personal video recorder))

Dynamic variable

Variable that is unstable in terms of a rapidly changing population profile. This is most likely to apply to equipment and other TV related variables (e.g. multiset homes, cable, DTH reception, digital reception, Internet access, etc.) during periods of strong growth.


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EACA (Europe)

European Association of Communications Agencies (formerly European Association of Advertising Agencies): European trade association for advertising agencies/media specialists.

EB (End break)

(see also Between programme break)

EBU (Europe)

European Broadcasting Union: International professional and trade association of national television and public radio service broadcasters in 52 countries in Europe, North Africa and the Middle East and 45 associate members in 28 countries from other regions.


Purchase of products and services over the Internet.

EDGE (Enhanced data rates for GSM evolution) or EGPRS (Enhanced GPRS)

Digital mobile phone technology that allows for increased data transmission rate and improved data transmission reliability. It is generally classified as a 2.75G network technology. EDGE has been introduced into GSM networks around the world since 2003, initially in North America.

Editing in/out

Phase of cleaning polled meter records (i.e. "raw" meter statements) during data processing/validation. The rules may either be for editing data in (varies largely for assigning uncovered viewing) or for editing data out (e.g. elimination of unassigned uncovered viewing, deletion or partial deletion of viewing records when concurrent viewing is encountered).

EEET (Cyprus / Greece)

Epitropi Elenhou Ereynon Tileorasis (TV audience research control committee): Joint industry committee of TV stations, advertisers, media buyers and market research companies supervising TAM data supply and surrounding technical issues in Cyprus and Greece.

Effective frequency

The level of exposure frequency at which reach is deemed "effectively" delivered. (see also Effective reach)

Effective reach

The number or percentage of a target audience that is exposed to a schedule of advertising spots at a set level of frequency. This will typically specify a lower threshold value indicating the minimum level of exposure deemed as sufficient for "effective" advertising purposes (e.g. 4+ reach) and an upper threshold (e.g. 12+ reach) above which additional exposures are considered as waste.

Effective sample size

The size of random sample that would provide the same standard error as the actual sampling plan on which a survey result is based. (see also effective/equivalent sample size)

Effective/equivalent sample size

Also termed equivalent, effective sample size denotes the estimated size of the sample based on sample error and after removing the effects of weights and dependencies within the sample caused by clustering (i.e. individuals within the same sample population living in the same household). In practice, measures of effective sample size are usually calculated by examining the effects of panel weights alone. For single audience measures, the effective sample will always be lower than the actual sample on the basis that, the greater the variability of panel weights within the selected sample/sub-sample, the lower the effective sample size. (see also Statistical efficiency value)


(see also Cost efficiency)

EGTA (Europe)

European Group of Television Advertising: European trade association of airtime sales organisations or departments representing the interests of about 100 TV stations in 26 countries in Europe (and Korea).

Electronic diary

Diary where respondents record their viewing on a small portable display screen using a light pen.

Elementary viewing data

Same as Disaggregated viewing data - processed viewing data held at the level of individual respondents.

Eligible address/ respondent

Contacted address/respondent that is eligible for selection within the sample.


Multimedia correspondence over the Internet.

E-mail advertising

Banner ads, links or advertisers sponsorships that appear in e-mail marketing communications.

Embedded gap

Term used in data editing to denote an interval of uncovered viewing sandwiched between two intervals of covered viewing.

Embedded signal

Supplementary signal (e.g. unique programme code, teletext code, genre code, etc.) contained in TV channel transmissions, which is not part of the audiovisual images appearing on the TV screen, but may be used by the viewer or other party for other purposes. TAM data suppliers may use it for channel or programme identification purposes.

EMRO (Europe)

European Media Research Organisations: International group of experts in national media audience measurement (mainly representatives of market research companies engaged in media research or members of industry committees overseeing media research).


In television, term refers to the process of transforming signals that requires specific decryption/decoding equipment to display them on the TV screen. Many domestic satellite channels, whether subscription or free-to-air, employ encryption for reasons of copyright. Pay-TV services employ additional conditional access technologies in order to restrict access to authorised (paying) customers and prevent signal theft or piracy.

Enforced (panel) turnover

Homes dropped from a panel on the initiative of the data supplier. The principal categories of enforced turnover are (a) turnover in order to preserve/improve panel balance, (b) turnover to reduce panel age as a precaution against creeping panel bias and/or panel fatigue (with some TAM systems setting a maximum length of service), or (c) turnover due to faulty compliance with panel viewing instructions.


Broad terms/buzzword referring to user involvement in the media being consumed.

Enhanced TV

Television programming supplemented with extra datacast materials and/or coverage options in order to enhance its appeal to viewers (e.g. drop-down menu displays giving details of accommodation and sightseeing opportunities at a holiday destination described in a travel programme).

Entry package

Minimum basic package of channels and services to which subscribers to analogue or digital pay TV services must sign up.

Enumeration survey

Survey aimed at providing a population count of households/ household size. Enumeration surveys may be conducted on their own, independently of any other survey (as in USA) or as the initial phase of an establishment or other survey phases, where they are used in order to (a) update population estimates and (b) provide a sampling frame of addresses for designating the establishment survey sample.

EPG (Electronic programme guide)

Also called IPG (Interactive programme guide) or ESG (Electronic service guide). The EPG is an on-screen listings guide of TV programming and other on-demand content and services which users may navigate by means of their television remote control handsets or other devices. The information contained in the EPG is broadcast metadata received and read by applications middleware in a set-top box. EPG’s may offer a wide-range of functions, such as browsing, genre or channel search, marking items for recording on a PVR hard disc, parental locks and so on.

Equipment/TV-related variable

Household variables designating the type of reception, number and type of TV sets and other audiovisual equipment in the home (e.g. ownership of VCR's, DVD's, video games consoles, PC's etc.). They may also be related to viewing habits (e.g. claimed weight or claimed balance of viewing).

ES (Establishment survey)

Large-scale survey for collecting establishment, demographic and other household data. The ES provides the basis for deriving population profile estimates and determining target profiles for selected panel control variables (unless taken from other external sources). The ES samples are also generally used as a source of addresses for panel recruitment.

ESOMAR (Europe)

European Society Association of Opinion and Marketing Research: Based in Europe, ESOMAR is a global association of marketing professionals, whose membership includes market research companies and associated organisations and individuals from all across the world.


Generic term for wide range of computer-based technologies underpinning communications between devices over local area networks (LANs). Originally devised for communication between computers over a cable co-axial network, it has developed into a complex technology that underpins the vast majority of local computer networks. Ethernet stations communicate by sending data in small packets that carry information about the address and source of the packet. Deployed globally, the Ethernet defines a set of wiring and signal standards for the physical communications, as well as two means of network access and common address formats. (see also LAN (Local area network))

Event trigger

Information included in a transmission stream that indicates the start and end points of a programme, commercial or promo.

Event types:

Classifications of broadcast types found in the TV environment. They can be major, like commercial and non-commercial, or detailed like spot, sponsor, announcement or programme.

Excess viewing

Measured daily individual viewing that exceeds TAM system threshold criteria of extreme length (e.g. 20+ hours). Many TAM systems employ excess viewing as a quality control criteria during data validation.

Exclusive reach

Individuals who, during the period of analysis, have watched only one channel for at least one minute.

Exit interview

Interview conducted with home leaving the panel, usually for future panel management purposes.

Expansion factor

(see also Weight factor)


AGB Nielsen Media Research's TV Events system module used to save the monitoring data in a format required by external applications such as analysis software and third party database systems.


A person's physical contact with an advertising medium or message. In the case of television, exposure to an advertising spot is treated as equal to the measured audience for that spot.

Extension option

Extra period (typically one or two years) that a TAM contract may run beyond its initial expiry date at the discretion of the contracting party.


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FCC (Federal Communications Commission)

US agency that regulates US communications services, including cable television, at federal level.

FDDI (Fibre distributed digital interface)

Standard for data transmission in a local area network (LAN) based on the use of optical fibre to transmit data at a rate of 100 Mb/s. FDDI technology is being made redundant by the Ethernet.

Fibre optic to the curb

Variant of FTTH where fibre optic cabling extends to the street, but conventional copper wiring is used for entry into the home. (see also FTTH (Fibre to the home))

Fibre optics

Technology of data transmission that involves the passage of optical signals along bundles of glass filaments with extremely low signal attenuation.

Field strength survey

A survey which is conducted by TV stations for measuring the transmission power of their broadcasts.

Fieldwork control

A procedure for checking the quality of data collection and ensuring that the survey procedures are being adhered to.

Fieldwork period

Interval over which fieldwork is being carried out.


Making files available as downloads over the Internet or other smaller networks. The term originally applied to client-server downloads, whereby PC users (clients) could access and download content from web sites (servers). Today, the term is used to describe peer-to-peer (P2P) exchanges or networks, by which files are stored on user PCs rather than on central servers, allowing files to be downloaded from multiple PCs. Users wanting to join P2P networks must download and install file-sharing software. Some organisations have adopted the P2P file-sharing model as a way of reducing demand on (and cost to) central host servers. P2P file-sharing has raised major concerns over piracy amongst rights holders, particularly music labels due to the ease of sharing small music files.


Technique of inserting an extra signal code in a source appearing on the TV screen that enables later recognition. The technique is typically used during video timeshift recording of TV channel transmissions for later identification of timeshift video playback.

First run

Or Premier; a term used for a programme that is broadcast for the first time in television.

Fixed position

Specification by the advertiser/media buyer of the commercial break (or even position within the commercial break in some markets) in which an advertising spot is to appear.

Fixed potentials

Apply to demographic groups used in the weighting matrix.

Flat screen TV

TV sets, lacking the conventional cathode ray tube, that can be hung on the wall like pictures.


The scheduling of advertising for a period of time, followed by a hiatus, then another "flight" of advertising.

FLO (Frequency of local oscillation)

Frequency emitted by tuner in TV set, which permits Direct frequency measurement (DFM).

Floating ad (Online)

Ads that appear within the main browser window on top of the Web page’s normal content.

FM (Frequency modulation)

The transmission of audiovisual signals in which the frequency of a transmitting wave is modulated as a function of its intensity.


Geographic, elliptically-shaped reception zone covered by the signal beam of a satellite.

Forced turnover

Refers to the process which stipulates a maximum period of time that a home can be on the panel. (see also Enforced (panel) turnover)

Foreign TV channel

Any TV channel that is either an overspill channel (e.g. cross-border terrestrial or satellite channel) targeted at viewers in a different country from the country of reception, or is targeted at an international audience regardless of the location from which it is broadcast.

Fragmentation (Audience)

When broad television audiences break into smaller segments due to multiple viewing choices and niche programming that targets particular demographics.


Television channels or services for which viewers do not have to pay a subscription or other fee in order to receive them.

Freeze frame

Pause display of a single (frozen) frame of video.


The average number of times that members of a target audience who have been counted at least once as viewers to a schedule of advertising spots (or sequence of programmes), have counted as viewers.

Frequency discount

A rate discount given to an advertiser who purchases a specific schedule within a specific period of time, e.g., six ads within one year.

Frequency distribution

Distribution showing the percentage of the target audience population who have viewed a schedule of advertising spots (or sequence of programmes) at each level of frequency.

FTA (Free-to-air)

Broadcast television channels that are free at the point of consumption. This category includes publicly funded channels (e.g. financed by the licence fee) and channels that are financed by advertising only or by a mixture of public funding and advertising revenues. It excludes any form of subscription or pay-per-view TV.

FtF (Face-to-face) interview

Methodology of data collection by means of a questionnaire, which an interviewer administers face-to-face with the survey respondent.

FTP (File transfer protocol)

Commonly used protocol for exchanging files from one computer to another over the Internet.

FTTH (Fibre to the home)

Wired broadband communications technology in which the entire network to the home is constructed out of fibre optic cable. Benefiting from a significant decline in material prices, FTTH is emerging as a viable two-way residential communications technology in several countries, including Japan, Hong Kong, Canada, Italy and the Nordic countries.

Fusion/Data fusion

Fusion/Data fusion is the process of matching two or more surveys, for example, a survey on television usage and another on product usage. This is done at the individual respondent level to create a single, unified database. From a business perspective, fusion is a way of making the best use of existing marketing information. It is a cost efficient way of getting the most out of existing databases to improve decision making. It is mainly used as a planning tool by agencies or as a sales tool for media owners. Although fusion has only been used in the US for a relatively short time, most European countries use fusion in media research and have done so since the late 1980s.


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GB (Gigabyte)

Unit of computer hard disc storage capacity equal to one billion (1,073,741,824) bytes; not to be confused with Gb (gigabit), which relates to data transfer speeds. C94 (see also Bit rate)

Gb / Gbit (Gigabit)

A unit of information or computer storage.

GEAR (Europe)

Group of European Audience Researchers; Association of audience research professionals within public service broadcasting organisations belonging to the EBU.

Generalist channel

General entertainment TV channel without specific thematic content.


The demographic description of people living in specific geographic regions and types of environment (e.g. settlement size, type of housing, etc.).

GGTAM (Global guidelines for television audience measurement)

International guidelines sponsored and published by the EBU in collaboration with the Audience Research Methods (ARM) Group comprising representatives from nine international trade associations or groups of professionals: ARF (USA); Canadian ARF; EAAA (now EACA); EGTA; EMRO; ESOMAR; GEAR; PETR; WFA.

GNU Linux

A Unix-like computer operating system.

Gold standard

Industry declared correct audience values, most often used in connection with viewer ratings. The object of laying down "gold standards" is to prevent disputes between buyers and sellers of commercial airtime over the correct audience figures that have arisen on account of them using different software yielding different estimates of viewing.


Verb denoting use of the Google search engine to find information on the Internet.

GPRS (General packet radio service)

Mobile telephony technology for GSM mobile networks that adds packet-switching protocols, shorter set-up times for ISP connections and offers the possibility to charge by volume of data sent rather than connect time. In addition to its use for MMS, SMS, WAP access services, GPRS can also be employed for Internet web access and e-mail services.

Gross audience

The Gross sum of all exposures (number of individuals/homes) without regard of duplication.

Gross impressions

(see also Impact)

Gross panel size

Total sample of panel households/individuals, regardless of whether or not they contribute to the reporting samples.

Grossing up factor

(see also Weight factor)

GRP (Gross rating point)

Unit of audience volume, which is based on the percentage of the target audience population that has viewed a transmission across a unit interval (usually minute by minute audience, but some TAM systems base their GRP estimates on the second by second audience). For example, a GRP of 10 implies an audience size that is equal to 10% of the audience being measured. Meanwhile the total GRP delivery of a schedule of advertising spots is equal to the sum of commercial GRPs/ratings across all the spots contained in the schedule. GRP totals or averages may be estimated for a wide range of different time periods, programme or commercial selections. For purposes of calculating commercial GRPs and making comparisons, commercial GRPs for each advertising spot are typically adjusted to a standard 30 second advertising spot interval.

GSM (Global system for mobile communications)

Most widely used 2G mobile telephony standard in the world that offers key benefits of high digital voice quality and low cost text messaging alternative to making calls. GSM interface: Interface between a meter and digital GSM phone connection.

Guard time

In the absence of event triggers indicating the start and end times of TV programmes, timeshift recording devices may be configured to start recording some time prior to the scheduled start and to continue for some time after the scheduled end in case of delays/overruns. The intervals in which the devices are programmed to record before and after the scheduled transmission constitutes the guard time.


Person not belonging to the household and in any case not part of the designated panel member set, who watches for a certain period of time a TV-set in a panel members home.

Guest viewing

Viewing by guests. Guest viewing is registered through specific buttons on the handset together with a limited set of characteristics (usually sex and age). Final data may be processed with or without guests, while target groups for which there is no information about guest characteristics may be processed only without guests.

Guest viewing button(s)

Button(s) on a remote control handset for registering guest viewing.

GUI (Graphical user interface)

A particular case of user interface to interact with a computer which employs graphical images in addition to text to represent the information / actions available to the user.


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HD (High definition)

(see also HDTV (High definition television))

HD Ready

Term used to describe TV sets that are capable of displaying HDTV images. Most importantly, the HD Ready label provides no guarantee that a TV set will actually be able to watch HD programmes; only that it can do so provided that it is also equipped with the necessary tuner for receiving HD images in the format in which they are being transmitted. In the case of digital HD transmissions that means either the viewer must own an iDTV set with the appropriate tuner, or acquire a set-top box that can convert the HD images for display on the viewer’s HD Ready screen.

HDCP (High-bandwidth digital content protection)

This is a form of digital copy protection developed by Intel Corporation to protect digital audio and video content as it travels across DisplayPort, Digital Visual Interface (DVI), High-Definition Multimedia Interface (HDMI), Gigabit Video Interface (GVIF), or Unified Display Interface (UDI) connections. The specification is proprietary, and implementing HDCP requires a license.

HDMI (High-definition multimedia interface)

This is a compact audio/video connector interface for transmitting uncompressed digital streams. It represents a digital alternative to consumer analog standards such as Radio Frequency (RF) coaxial cable, composite video, S-Video, SCART, component video, D-Terminal, and VGA. HDMI connects digital audio/video sources such as set-top boxes, Blu-ray Disc players, personal computers, video game consoles, and AV receivers to compatible digital audio devices, video monitors, and digital televisions (DTV).

HDTV (High definition television)

Television broadcasting systems with notably higher resolution than conventional standard definition television (SDTV) systems. In order to achieve higher resolution HD broadcasts, a much greater bandwidth capacity is required, which has been facilitated by the development of digital compression technologies. The term is also relative. Three main factors define HDTV broadcast systems: (1) Vertical display resolution (mostly today 720 or 1080 lines, versus 525 in the American NTSC SD format, or 625 for the European PAL and SECAM formats); (2) Scanning system (progressive or interlaced); (3) Number of frames transmitted per second (from 24 to 60 Hz today, depending on the system). The actual quality of HD broadcast will depend on several factors, such as how well operators follow the technical specifications. The superior quality of HD over SD signal quality also becomes steadily more noticeable with larger screen sizes.

Head of household

Demographic category employed in TAM research that denotes the individual (adult) with main responsibility for the household. According to convention, the head of household will always be male where there are one or more male and one or more female adults living in the household (e.g. always the husband in households occupied by married couples). By definition, each household has one and one only head of household.


The control centre of a cable television system where incoming transmissions are received, processed, converted and re-transmitted across the cable network.


Protocol control information located at the beginning of a protocol data unit.

Heavy viewer

Person whose average daily viewing levels satisfy TAM system threshold criterion for classifying that person as a "heavy" viewer.

HFC (Hybrid fibre-coaxial)

A wired network combining fibre-optic with coaxial cable. HFC is the most commonly found wiring format of cable television systems, where the main trunk cables and larger feeds consist of high capacity fibre optic wires, whilst the local feeds to the home are coaxial.


Commonly used abbreviation for Household or Home, the two terms being equivalent.


A period of non-activity - the period between advertising flights.


Unit measure of download requests received by a server when users access a Web site. Each element of a requested page (including the page itself, graphics, text and interactive items) is recorded in the Web server as a hit. The object is to measure the workload at a server and the number of hits registered during a session may bear no relation to the number of pages being downloaded.

Home page

Page designated as the main point of entry on a web site, appearing at the start of a user session. Home pages will typically offer a welcome, explanatory text about the site and offer links to other sites.

Home shopping

On-screen shopping services that may take the form of TV broadcast channels dedicated to home shopping as well as additional interactive text and services.

Homes connected

Number of homes connected and subscribing to one or more services offered by a cable network, including cable television.

Homes passed

Number of homes passed by a cable network that can be connected to it and are available for marketing.

Hours of transmission

Number of hours per day during which a television channel is on air (i.e. transmits programming). The total may vary by day of week or by region.

Hours of viewing

The average daily/weekly number of hours of viewing by a selected audience category to a given TV channel or in total across a selected interval (usually monthly, quarterly or annually).

Housewife/ housekeeper / Household shopper

Widely employed demographic classification that specifies the person in panel household claiming primary responsibility for the household’s grocery shopping. Precise definitions vary. For example, some systems specify one and only one housewife/housekeeper per household, who may be a man or woman. Others may specify that the housewife/housekeeper has to be a woman, and so on.

Hover ad (Online)

Pop-up ads that do not scroll with the page, but appear to hover above it, as the page moves underneath.

HSDPA (High speed downlink packet access)

Advanced 3G mobile telephony protocol enabling UMTS-based 3G networks to achieve higher transmission rates as compared with the standard W-CDMA protocol.

HTML (Hyper text markup language)

Predominant programming language for combining text with images that enables the creation of web pages, mostly for delivery via HTTP servers or e-mails.

HTTP (Hypertext transfer protocol)

Communications protocol for the transfer of information on intranets and the World Wide Web, whose function is to transfer information from a web site server for display on in the user's web browser.

HUT (Homes using TV)

Term mainly used in the US that refers to the percentage of homes using (tuned in to) TV at a particular time.

Hybrid (television) services

Television services that combine signals from more than one delivery mode: invariably satellite or terrestrial broadcast reception plus broadband DSL delivery of on-demand, Internet and other services.


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Interactive Advertising Bureau: Industry association in the USA representing more than 375 companies that are actively engaged in and support interactive advertising. The IAB has taken a leading role in publishing standards of online advertising and measurement practice.


Also termed HC-SDMA (High Capacity Spatial Division Multiple Access), iBurst is a wireless broadband technology that optimises band width use with the help of smart antennas.

iDTV (Integrated digital TV)

TV sets with in-built converters that can receive and display digital TV channels transmitted in the clear without the need for set-top boxes.

IEEE (Institute of Electronics and Electronic Engineers)

World’s largest international non-profit professional organisation, comprising 360,000 members in about 175 countries and responsible for developing and certifying international standards.

IM (Instant messaging)

Real-time instant text communications between two or more users via a network, such as the Internet.


Unit measure of commercial audience delivery, with one impact being equal to one person's viewing of one 30 second advertising spot. Impacts also referred to as gross impressions.

Impact delivery

Sum of impacts across a schedule of advertising spots. Impact delivery is most commonly used as a measure of the total commercial audience delivered by a TV channel.

Impact weights

Weights applied to advertising spots of different lengths in order to adjust them to the standard 30 second length. Impacts may be weighted by (a) duration (e.g. impact delivery of a 15 second advertising spot treated as equivalent to 50% of its value for a 30 second advertising spot) or (b) ratecard prices (e.g. impact delivery of a 10 second spot with a ratecard price that is 50% of a 30 second advertising spot, being treated as equivalent to 50% of its value for a 30 second advertising spot).


(see also Ad impression (Internet))

IMT-2000 (International Mobile Telecommunications-2000)

Global standard adopted by the ITU for third generation (3G) wireless communications.

In directory sample

Installed base of panel households equipped with meters less homes that are out of production for long periods and have been classified as off directory. The in directory sample may include some out of production homes that are under observation (e.g. newly installed run-in homes or homes with technical problems that are under repair), being polled but not produced in the daily reporting sample.

In home viewing

TV viewing that takes place in the home.

In production sample

Meter panel households that are available for polling and inclusion in the net daily reporting samples.

In vision teletext

Teletext superimposed on the normal broadcast picture (as with subtitles for hard of hearing).

Independent station

A commercial TV station serving a regional/local market that is independently owned, although it may be affiliated with a network.

Individual viewing statements

Converted meter records (raw data) after data processing (i.e. after editing, validation and assignment of weights) into summary statements of individual viewing over time. Each statement contains information concerning (a) Start and end time of the viewing session; (b) identification of signal source and TV set being viewed; (c) identity of viewer; (d) coded demographic and other information about the individual's identity; (e) the individual's daily weight. Processed individual viewing statements constitute the basic components of disaggregated viewing data.


An extended commercial message, usually lasting from 90 seconds up to two minutes. Features product/service information, including product demonstration.

Installation date

The date when a recently recruited meter panel household is installed with one or more meters for measuring TV viewing.

Installed base (panel homes)

Gross panel sample comprising all TV homes equipped with meters (setmeters or peoplemeters), including some off directory homes, which are out of production for long periods.

In-tab sample

(see also Net daily reporting sample (in-tab sample))

Intelligent agents

Software tools that help Internet users locate information/services, making recommendations based on the user’s profile, which is continually refined over time.

Interactive advertising

Advertising which allows for viewer interaction with on-screen image using the remote control handset in order to access further information or other materials. Interactive advertising is restricted to digital television services.

Interactive cable

A cable system with two-way communications that allows the cable TV viewer to respond (interact) to what is being telecast via a remote control handset, which transmits his/her messages directly to the cable operator.


Two or more different cable systems which are linked together to air locally sourced programming or commercials simultaneously. A "hard" or "true" interconnect is linked by cable or microwave. A "soft" interconnect is a group of systems with an agreement to insert commercials into programmes or time periods.

Interlaced scanning

(see also Progressive scanning)

Interlocking variables (weights)

Variables employed in (cell-matrix) combinations for weighting survey data (e.g. Age x Sex x Region).


Worldwide network of interconnected computer networks that is open to everyone. The networks transmit data by packet-switching using the standard Internet Protocol (IP).The Internet can be used to access the World Wide Web, along with file-sharing and e-mails.

Internet backbone

Refers to the main 'trunk' connections of the Internet. It is made up of a large collection of interconnected commercial, government, academic and other high-capacity data routes and routers that carry data across the countries, continents and oceans of the world.

Internet Television

Television programming that is publicly available over the Internet.

Interview call-back attempt(s)

Maximum number of attempts that an interviewer will make in order to request an interview at a designated household address or telephone number after receiving no answer on previous attempts.

Interviewee selection

Method of selecting interviewees using household addresses or telephone numbers.

Invalid data capture

Collection of meter data in a mode different from the established mode for data processing.

Invalid meter statement

Meter statements from devices other than the established ones or statements that do not observe the established formats in other respects (e.g. wrong dates).

IP (Internet protocol)

Protocol for sending data over a packet-switching Internet network. It is a network layer protocol contained in a data link layer protocol (e.g. Ethernet) that supplies the communicability between computers, using a unique global addressing system. In contrast to the Ethernet, which also works with unique addresses, IP specifies the final destination. The Ethernet is only concerned with getting the device to the next link in the chain (e.g. wireless router).

IP multicast

Method of distributing content to multiple destination end user PCs (or TV sets connected to a network delivering IPTV signals).


A brand of Portable Media Player, created by Apple Computer. (see also Portable Media Device)

IPPV (Impulse pay-per-view)

Variant of pay-per-view, which lets consumers order PPV programming directly via their remote control handsets and clicking at the TV screen rather than having to make a separate telephone call.

IPTV (Internet protocol television)

This is a system where a digital TV service is delivered using Internet protocol over a network infrastructure, which may include delivery by a broadband connection. A general definition of IPTV is television content that, instead of being delivered through traditional broadcast and cable formats, is received by the viewer through the technologies used for computer networks. For residential users, IPTV is often provided in conjunction with VOD and may be bundled with Internet services such as Web access and VoIP. The commercial bundling of IPTV, VoIP and Internet access is referred to as "Triple Play" service (adding mobility is called "Quadruple Play"). IPTV is typically supplied by a service provider using a closed network infrastructure. This closed network approach is in competition with the delivery of TV content over the public Internet, called Internet Television. In businesses, IPTV may be used to deliver television content over corporate LANs.

ISDN (Integrated services digital network)

Telephone network that employs digital switching and transmissions. Compared with analogue networks, which they already replaced in many countries, ISDN systems offer much higher data transmission rates, but lower than the more recently introduced DSL technologies, which have become increasingly popular for fast speed Internet access.

ISP (Internet service provider)

Company offering Internet connections to individuals, companies and other organisations. An ISP may provide Internet access via a number of different technologies with varying connection speeds and levels of service quality, including telephone dial-up, ISDN, DSL and cable.


AGB Nielsen Media Research's expanding suite of tools available for the management, optimisation and control of operational resources and assets specific to the Television Audience Measurement (TAM) environment. The tools presently include the management of assets and deployment and scheduling of field resources.

ITU (International Telecommunication Union)

Global international telecommunications organisation established to standardise and regulate international radio and telecommunications, including organisation of interconnection arrangements between different countries.


PC jukebox and store software application that allows users (1) to organise and play music and other media files and (2) to purchase music, video and other content from Apple. The contents stored on iTunes can be transferred and played on iPods.

iTV (Interactive television)

Television services that permit viewer interaction. The concept of interactivity can be applied at many different levels. In the field of digital television, it currently refers to services that allow viewers to choose and control extra coverage options or make use of other interactive services directly with their remote control handsets.


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Widely used general purpose computer programming language developed by Sun Microsystems. Programmes written in Java can run on any platform, including set-top boxes, provided they contain a Java Virtual Machine.

JIC (Joint industry committee)

Form of survey organisation in which a joint industry grouping of TV station, advertiser and media buyer representatives holds a contract with one or more data suppliers for a fixed time period (usually lasting between five and ten years). The functions of the JIC generally include contract specification, supervision of the TAM service, ownership of data copyright and determination of the conditions of data release.

JICTAR (Malaysia)

JIC responsible for TAM data provision in Malaysia.


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Keyword (Internet search)

Word used as a link for finding matching pages with the help of a search engine, most often in connection with web search.

Keyword bucketing

Online pay-per-click advertising procedure of grouping all keywords into common categories and writing a specific ad for each keyword bucket.

KPI (Key performance indicators)

Used in the audit process to measure the performance of the panel against agreed standard measures of performance.


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LAN (Local area network)

An independent Network allowing the interconnection and intercommunication between computers on a single site (such as home, office and group of building).

Large-screen television techology

Collection of different technologies that allows the display of television pictures on large flat screens. Early adopted examples include Plasma display (PDP), Liquid crystal display (LCD) and Digital light processing (DLP). Each of these has presented certain drawbacks and new technologies are being developed that will make the current well-known front runners obsolescent. They include Organic light-emitting diode (OLEP), Surface-conduction electronic-emitter display (SED) and Field emission display (FED).

Last mile

The final leg of delivering connectivity from a communications provider to a customer. Usually referred to by the telecommunications and cable television industries, it is typically seen as an expensive challenge because "fanning out" wires and cables is a considerable physical undertaking.

Lazy viewing

Form of uncovered viewing in which no family member registers his/her presence for an entire viewing session when the TV set is on. Many TAM systems employ lazy viewing above set threshold values as a quality control during data validation.

LCD (Liquid crystal display)

Thin flat-screen display made up of many pixels, each comprising a molecular crystal layer between two transparent electrodes and two polarising filters. Without the middle layer, light would not pass through the two polarising filters, but is able to do so through rotation as it passes through the crystal layer, with variations being determined by externally applied voltages. The LCD technology has many applications from simple black and white displays on watches and calculators to high-resolution large-screen computer and television displays. (see also Large-screen television technology)


A programme preceding/following the time period of the programme being analysed.

Leading gap

Term used in data editing to denote an interval of uncovered viewing at the beginning of a TV viewing session that is followed by an interval of covered viewing.

Lean back/lean forward

Terms use to describe the different modes of engagement that users adopt with media. Television may be regarded as a lean back medium, involving minimum interaction with the viewer, who sits passively and waits to be entertained, while the laptop is a lean forward medium, requiring constant interaction between the user and the materials being displayed on screen.

Licensed software

Application software for analysing viewing data for programming/advertising purposes that has been licensed to the data supplier (or other party delivering data to the market) by a separate, independent company.

Licensed user

A client organisation subscribing to the TAM viewing data. Fees may be variable depending on the level of access required.

Life stage

Household classification based on time of life characteristics of family (e.g. young couple without children, family with young children, retired person/couple with grown-up children who have left home, etc.).


Classification variable based on individual behaviours, such as leisure activities, recreational habits or product purchase/ consumption behaviours.

Light viewer

Person whose average daily viewing levels satisfy TAM system threshold criterion for classifying that person as a "light" viewer.

Linear TV

Umbrella term for real time television services that transmit programme schedules. Almost all broadcast TV services count as linear TV, the main exception being Near video-on-demand (NVOD) transmissions of pay-per-view programmes over a large number of channel feeds. The alternative non-linear TV covers all on-demand programming, which is available to view at any time the user decides and not constrained by real-time broadcast schedules. The linear versus non-linear TV distinction may also be applied to the nature of viewing, whether it is live (linear) or timeshift (non-linear).


The listing of stations carrying a TV programme.


Technically termed hyperlink, link refers to the clickable connection between two web sites.


(see also GNU Linux)

Live audience

The audience of a commercial, daypart or programme at the time of its actual transmission.

Live banner (online)

Dynamically created Internet ad banner, which changes in real time.

Live ratings

An innovative system for TAM data delivery, developed by AGB Nielsen Media Research. Provides any time, any place, real-time minute-by-minute audience data for immediate programme evaluation.

Live streaming

Multimedia content transmitted over the Internet that begins playing upon the arrival of the first packets and simulates real-time delivery.

Live viewing

Viewing of live broadcasts at the actual time of transmission, therefore not including any playback or time shifted viewing.

LLU (Local loop unbundling)

Regulatory process letting multiple telecommunications operators with different customers assume control from the network owner of the twisted-pair connections running between the local telephone exchange and their customer premises. Under shared LLU, the operator only controls the broadband connection. Under full LLU, the operator controls the telephony connection as well.

Local feed

TV channel transmissions that are modified in order to meet the needs/requirements of a specific market segment (e.g. Pan European channels with different language feeds and/or variations in programming/advertising to cater for different national markets.

Local loop

In telephony, the physical circuit running between the customer premises and the local telephone exchange.

Local TV

TV services serving local communities/sub-regions.

Local window

The broadcast of local contents overlapping the national contents in a simulcast or shuffle cast station.

Log proof

(see also Commercial and programme logs)

Longitudinal data analysis

Analysis of disaggregated viewing data, that is based on individual viewing records over time. Key output measures are audience reach and frequency, although longitudinal analyses can, like cross-sectional analyses, also supply estimates of ratings, amount of viewing and audience share.

Low pay

TV services that are part of a basic subscription package giving a low average cost per channel.


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Main shopper

Widely used demographic classification that specifies the person in the household who is mainly responsible for purchasing household goods. As with housewife/housekeeper, precise definitions vary across different TAM systems.


Extra advertising spots in compensation of a scheduling error/alteration by the TV station or failure to deliver an audience guarantee target during the campaign period.

Master meter

Installed meter that has extra functions of collecting and storing data from other installed meters in the household, which it delivers to the central processing base of the data supplier during polling.

MATV (Master antenna television)

Mini-cable system connecting multiple homes on a single premise (e.g. apartment block, housing estate) to a central collective antenna for picking up terrestrial over-the-air signals.

Maximum to minimum weight ratio

The ratio of the individual with the highest weight to the individual with the lowest weight in a survey sample. For proportional samples, the maximum to minimum weight ratio provides an important index of the variability of a sample or its degree of balance. In general, the better the balance, the lower the ratio. For disproportional samples a high weight ratio is mainly derived from the different sampling rates.


(see also Bitrate/Bit rate)


Arithmetical average calculated by summing numerical values across a list of items and dividing the sum by the number of items on the list.

Mean weight

The average weight of individuals or households within a sample. Most TAM systems are only concerned with individual weights, as viewing is nearly always reported for individuals rather than households.

Media buyer

Agency responsible for purchasing commercial airtime on behalf of advertisers; they also often provide support to the advertisers for planning, optimisation and control of the performances.

Media dependent

Media planning/buying specialist dependent on a creative agency with common ownership.

Media independent

Media planning/buying specialist on behalf of creative agencies under separate ownership.

Media mix

The distribution of time and money allocated among TV, radio, print, Internet and outdoor advertising that makes up the advertising campaign.

Media owner

General term for companies or organisations that own TV stations. In TAM research, it is used more broadly to include TV stations, TV airtime sales houses, programming organisations, trade associations or other parties belonging to the television sector.

Media player

Computer software for playing multimedia files that may be general or specifically tailored for a particular type of file (e.g. audio or video player) with an emphasis on the quality of the user experience.

Media schedule/plan

A plan for an advertising campaign which specifies details of the selected media, advertising content, dates and timing dates.

MediaFLO (Media-forward-link-only)

One-way mobile TV technology developed by Qualcomm in the US that uses a different frequency from current cellular networks for transmission to portable devices such as cell phones and PDAs.

Médiamétrie (France)

Private research company under tripartite ownership operating TRCC in France. It both acts as TAM data supplier and sub-contracts some fieldwork to other parties. Médiamétrie includes non-shareholders in its supervisory committees.


An additional item of data about the data being transmitted; commonly used to refer to EPG and other information contained in TV signals. (see also SI code (Service information code))

Meter (TAM research)

Any automatic recording device that monitors the tuning status of the TV set (set on/off, time, duration and channel) to which it is attached.

Meter sensitivity

Timelines with which meters can detect changes in set use: typically in the order of one second or less.

Meter time drift

Time difference between the meter clock and the central computer clock of the data processing system, as registered during data polling.

MFN (Multi-frequency network)

TV transmission network employing multiple frequencies, often to provide different regional network services.

MHP-DVB (Multimedia home platform)

Open middleware standard devised by the DVB project for supporting interactive, Java based applications on the TV set. These include EPG navigation, interactive games, betting, home shopping, voting, SMS and e-mails. MHP set-top boxes may also provide return pathways for applications like home shopping and voting that require backchannel communications with the outside world.


Computer software for connecting software applications, in particular used to support interactive applications.


Online video advertising where the advertising commercial plays in a break during the content video play.

MIE (Main income earner)

Demographic classification that specifies the person in the household who earns the main income providing for the needs of the household.

MIMO (Multiple input and multiple output)

Smart/intelligent antenna technology involving the use of multiple antennas at both the transmission and receiver to improve performance, and without requiring additional bandwidth or transmission power.


TV channels, usually offered in small packages, that carry an extra charge on top of basic subscriptions, but cost less than premium TV channels.

Minute attribution

Method commonly used in peoplemeter research of assigning each clock minute of measured viewing to a particular service (e.g. Channel X) or group of services (e.g. video or "other" use). Attribution is made with the use of selected algorithms, which may have variable definitions (e.g. attribution based on majority recorded use during the clock minute, or the last recorded use during the clock minute) and time thresholds for assigning use.

MMDS (Multichannel multipoint distribution service)

A common microwave carrier service operating in the 2GHz to 3GHz band used either to network programming to local distribution points such as hotels or cable headends, or as an alternative or extension to cable systems, for example in sparsely populated rural areas.

MMS (Multimedia messaging service)

Telephony system standard that permits users to exchange multimedia messages, including images (e.g. photos) and video, and not just confined to short text messages, as with SMS.

MMS (Sweden)

Mediamatning I Skandinavien: Private research company under tripartite ownership (mostly media owners) operating TRCC in Sweden. MMS contracts data provision to external data suppliers, but controls the marketing and release of the data to client users.

Mobile browser

Web browser designed for a mobile device such as a mobile telephone or PDA.

Mobile TV

Television services for delivered over broadcast or mobile telecommunications networks for reception on mobile handsets. Several candidate technologies exist for broadcasting TV to mobiles (viz. DVB-H, DMB, TDtv and MediaFLO). Each presents some drawbacks and a winner has not yet emerged.

Mobile video download

Download of video content to mobile handsets.


A mobisode (from mobile + episode) is a specially created mini-television series suitable for showing on the two-inch phone screen of these new handsets.

MOC (Media owner contract)

Form of survey organisation in which one or more media owners (i.e. TV stations, including airtime sales houses) holds the main contract with the data supplier that guarantees the production and delivery of TAM data. MOC systems vary appreciably in terms of how far the media owners involve themselves in the supervision of the TAM services or in determining commercial policies for releasing TAM data to other parties.


The most frequently found numerical value in a series of items with associated numerical values.


A modulating and demodulating device that converts digital signals for transmission (e.g. for sending/receiving faxes or e-mail via the telephone network).


MP3 (MPEG-1 audio layer 3) is popular digital audio encoding technology using highly efficient (MPEG) compression algorithms that capitalise on discarding less audible sound components.

MP3 player

A Digital Audio Player (DAP) for organising storing and playing MP3 digital music files

MPEG (Motion picture experts group)

Working group belonging to the ISO (International Standards Organisation/IEC (International Electrotechnical Commission) and responsible for the development of the MPEG family of video and audio encoding standards; examples including MPEG-1, MPEG-2, MPEG-3 (now abandoned) MPEG-4, MPEG-7 and MPEG-21.


A recent compression standard for audio and video signals adopted in 2000 and developed by the Moving Pictures Expert Group (MPEG). MPEG-4 subsumes and surpasses MPEG-1 and MPEG-2 by adding advance features, including 3 D video images, HD and various forms of interactivity and externally-specified DRM support. Of special importance for IPTV, MPEG-4 promises to create full interoperability over the Internet, dispensing with the need for content providers to encode in multiple formats. Its greatly superior bandwidth efficiency has seen it adopted already by the satellite broadcasters such as DirecTV and the DVB, as well as by licensed digital terrestrial broadcast pay-TV services in France.


Media Research Council: multimedia joint industry body, whose functions include auditing and commenting on the quality and accuracy of TAM data.

MSO (Multiple system operator)

Cable operator that operates multiple cable TV systems.


The broadcast of messages to a selected group of workstations on a network


Broadcasting of several programmes at the same time on a digital TV channel.

Multichannel TV home

TV homes that are equipped to receive extra TV channels in addition to the locally available free-to-air terrestrial analogue channels. The extra TV channels include additional cable and satellite analogue channels as well as extra digital satellite, cable and terrestrial channels and services.


Digital recorder of the AGB Nielsen Media Research's TV Events system, recording and storing the audio/video database. The Grabber hosts the ASR (Automatic spot recognition) engine. The Grabbers run under the Linux operating system in a non-attended environment. A Grabber can store up to 40 days of full quality digitalised audio/video, or up to 180 days in limited quality.


Media applications that employ multiple formats (e.g. video, audio, text, graphics, animation, interactivity etc.).

Multimedia buys

The purchase of advertising in more than one medium owned by a media supplier, or by media suppliers who have a cooperative agreement. Multimedia buys can encompass multiple media vehicles within a media form (e.g. several magazines) or different media forms (e.g. magazines and TV).

Multi-platform home

TV home that can receive extra channels in addition to the locally available free-to-air terrestrial analogue channels via more than one distribution platform.


Term used in digital television to refer to a single carrier frequency that is used to carry several digital channels simultaneously by means of compression technologies. The onset of digital television created a challenge for TAM systems using DFM methods for identifying channel tuning.


Process widely used in digital television broadcasting (but also possible in analogue) of squeezing multiple channels on to a single frequency by means of digital compression technologies. The signals are subsequently demultiplexed at the point of reception (usually by means of a set-top box). Basic multiplexing variants include time-division multiplexing (TDM) and frequency division multiplexing (FDM).

Multiset homes

Homes with two or more TV sets.

Multi-stage stratification

Sample stratification in more than one step (e.g. stratification by region/sub-region followed by stratification by settlement size, etc.). (see also Stratification)


Commonly used abbreviation for multiplex.


Well-known interactive, social networking web site purchased by News Corporation that allows users to build up a network of friends with whom they can exchange all kinds of materials and create their own personalised profiles of favourite film makers, musicians and assorted media celebrities who contribute to MySpace.


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National Association of Broadcasters: National trade association of TV broadcasters in USA.


Relative to broadband, narrowband systems carry a narrow frequency range (sometimes defined as bandwidths less than 1 MHz). Voice telephony (3 kHz) is an example of a narrowband system and television (6 MHz) an example of a broadband system.


TV transmissions via a wired network (e.g. cable television system, telephone network, etc.).

Natural (panel) turnover

Panel turnover due to natural causes (i.e. not enforced by the data supplier), of which the principal category is resignation by the panel household; but also moving house or severe technical problems may be causes of natural turnover.

Net daily reporting sample (in-tab sample)

The final sample yielding audience measurement data on a given day after polling and validation: It is equal to the in production sample less households that were not successfully polled and households that were successfully polled, but rejected during validation for technical or behavioural reasons.


A broadcast service, usually covering a large geographic area, composed of a number of TV stations that broadcast a mixture of central "network" and regional/local programming and/or advertising. Many different types of networks exist in terms of ownership ties, programming and commercial agreements, management structures and market coverage. Affiliate networks are commonly found in geographically large countries like Australia, Brazil, Mexico, Russia and the USA. In Europe, where national land areas are much smaller, a number of countries have regional/local TV networks, mostly publicly funded and under central state ownership.

Network DVR/Network PVR

Performance of DVR/PVR functionality by a network client server instead of by a DVR/PVR device in the user's home.

Network overlap

Signal overlap of TV stations belonging to the same network.

NGA (Next generation access)

Used in telephony, NGA refers to the application of more advanced technologies that will allow the upgrade of local loops to provide faster broadband data rates. This generally involves laying fibre-optic cable beyond the local telephone exchange, either to a roadside cabinet or directly to an end user’s premise.

NGN (Next generation network)

General term for advanced packet-switching computer network architectures that are beginning to emerge, covering voice and data communications, but with the optional use of other functions, such as carrying video signals. NGNs are to use Internet technologies and involve a more defined separation of the transport functions of the network from the services that ride on it.

Niche channel

Thematic TV channel catering for a specific interest group (e.g. children's channel, DIY channel, etc.) and usually targeting a specific audience demographic subgroup.

Nil viewing

Processed daily viewing statements without any registered viewing. Nil viewing may refer to (a) household nil viewing, (b) individual nil viewing or (c) nil viewing by TV set. The different types of nil viewing may all be used as quality controls for checking sample compliance with the button-pressing instructions.

NMS (National media survey)

National media survey covering one or more of the main display advertising media (usually at least print media or radio). A number of European countries use NMS’s that employ interview methodology with large samples as an alternative to establishment surveys.

Non-interlocking variables (weights)

Variables employed on their own, independently of other variables in weighting survey data (e.g. Age on its own, Sex on its own, Region on its own).

Non-intrusive meter

Meter that can be installed without any interference with the TV set or other equipment to which it is attached.

Non-linear TV

Alternative to linear TV. (see also Linear TV)

Non-standard set use

Use of TV set for purposes other than viewing conventional live broadcast/narrowcast programming (e.g. channel tuning via VCR, timeshift video recording and playback, pre-recorded video cassette viewing, video games, etc.).

Non-terrestrial TV

TV channels that are both distributed to TV homes via satellite or cable satellite. Precise definitions may vary from country to country. In the UK, for example, non-terrestrial TV is often used to refer to all channels, including DTT-only channels, apart from the five national/regional terrestrial analogue services. Elsewhere, there may be a question of whether channels like MTV, which are broadcast via satellite, received by an intermediary station and re-broadcast terrestrially, should be classified as terrestrial or non-terrestrial. It is a matter of deciding which distinction is most useful in the country or market concerned.

NPM (Non-programme minuteage)

The number of minutes of non-programme content screened over a specified period.

NPVR/Network PVR

Form of PVR/DVR, where the viewer stores programming on the network server of a service operator (i.e. TV-over-DSL operator) as opposed to a hard disc in the viewer’s PVR/DVR in the home. Although the two forms of PVR may function in the same way, they may invlove significant legal issues with regard to programme licensing/copyright. (see also PVR (Personal video recorder))

NSV (Nullsoft streaming video)

Media container designed for streaming video content over the Internet. NSV was developed by Nullsoft, the makers of Winamp. The NSV format is another example of streaming video formats, offered by various companies and media players. Windows Media, QuickTime video, RealAudio and RealVideo streams are just a few examples of these.

NTP (Network time protocol)

A protocol for synchronising the clocks of computer systems over packet-switched, variable-latency data networks. It is designed particularly to resist the effects of variable latency (jitter buffer).


US technical broadcast standard for analogue TV transmissions named after the National Television Systems Committee.

Number of days polling

Number of days allowed for the collection of definitive viewing data. Where more than one day is allowed, data polled on the first day are augmented with data from homes that were not successfully contacted on the first polling day, but were successfully contacted on subsequent polling days (usually a small addition that improves the overall production levels).

NVOD (Near video on demand)

Restricted form of on demand programming, where the programmes made available for selection are broadcast at staggered (e.g. 15 minute) intervals on a group of channels, so that the viewer can choose the most convenient start-time. PPV services offering premium films are a form of NVOD, as the same film is transmitted a large number of times. NVOD services do not necessarily carry a subscription charge.

NZTBC (New Zealand)

New Zealand Television Broadcasters Council: An industry organisation representing the non-competitive interests of the free-to-air broadcasters in New Zealand.


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Obb (Opening break bumper) / Cbb (Closing break bumper)

A term used for a short bumper slide (usually 5 second) placed at the beginning of a commercial break (Obb) or at the end of a commercial break (Cbb).

OCR (Optical character recognition)

Computer software designed to translate images (usually captured by a scanner) into either machine editable text or to translate pictures into a standard encoding scheme. Often used in the field of pattern recognition.

Ofcom (UK)

The independent regulator and competition authority for the UK communications industries, with responsibilities across television, radio, telecommunications and wireless communications services.

Off air

Events/promotion to support a TV programme, which are not broadcast on TV.

Off directory

Installed meter panel households that are out of production because they cannot be polled (e.g. cannot be polled due to non-payment of telephone bills, moving house, undergoing house alterations, problems with the modem of the meter, etc.). The precise criteria for placing homes off directory vary across panels.

Official source(s) of population statistics

National sources of population estimates, such as census data (including interim projections of changes in population size and distribution) or personal or household population registers that are used as basic reference sources for arriving at population estimates. The quality of official statistical sources and the degree to which TAM systems borrow from them vary appreciably across different countries.


Beyond the reach of a specified network. Term has varying meanings depending on the network under consideration. It is commonly used with reference to LLU telephony networks, where off-net customers refer to customers which the network service operator cannot reach directly using its own network, but finds an alternative solution (e.g. CPS (Carrier Pre-Selection)) for delivering its services.

OMD (Online movie download)

Movies that are delivered to the user’s hard disk storage via IPTV downloads.

Omnibus survey

Regular or periodic survey containing a variable battery of questions covering a heterogeneous selection of subjects. Such surveys are occasionally used by TAM systems for collecting establishment data.

On air

Events / promotion that aired / broadcasted on TV.

On-demand Service

A type of telecommunication service in which the communication path is established almost immediately in response to a user request brought about by means of a user-network signalling.

On-demand streaming

Service whereby users may receive audio or video content by streaming on-demand via a network, but where the user can select the time and place of reception.

Online advertising

General term for advertising on the Internet. The three main forms constitute search, classified and display.

Online producer

Company or organisation responsible for creating/assembling, arranging and editing the text, image, video and audio materials on a Web site.


Within reach of a specified network (see Off-net). On-net customers of a network service operator are customers directly connected with that operator's network. (see also Off-net)

Optimisation software

Campaign planning software that aims at achieving the best spread of commercial airtime across the spot schedule with respect to selected audience objectives.

OS (Own service)

Form of survey organisation in which the data supplier operates the TAM service as a private enterprise, holding multiple contracts of varying lengths with individual client subscribers. It is the most common form of TAM data provision, especially outside Europe.

Other viewing

The residual reporting category of TV viewing after subtracting all identified and separately reported viewing from named TV channels and other applications. Usually, only viewing to named channels is reported, while the precise definition of the other viewing categories will vary across TAM systems, depending on what it is decided to include under total viewing and what the TAM services chooses to discard altogether.

OTS (Opportunity to see)

A commonly used term in Europe denoting frequency of media exposure. For television it is synonymous with frequency.

Out of home viewing

All viewing that takes place outside the home (e.g. viewing at a friend's house or at a public venue, such as in pubs, clubs, hotels or work places). Out of home viewing may be particularly important for some broadcasters, e.g. niche satellite channels.

Out of production sample

Installed meter panel households that are not available for production, because they have been classified as off directory or have been withheld for other reasons (e.g. newly installed run-in homes or homes with technical problems that are being monitored, etc.).

Overnight viewing data

Viewing data delivered the next day. The term is sometimes used in a narrower sense to refer to initial data output covering a restricted selection of key target audiences that is delivered to clients at the earliest opportunity the next day (i.e. during the morning).

Overspill station

TV station, which can be received outside its target market or geographic coverage area. The overspill may be national (see Cross-border overspill) or regional/local and likewise broadcast or via cable retransmission. (see also Cross-border overspill)

Own software

Application software for analysing viewing data for programming/advertising purposes that has been developed by the data supplier or other party delivering data to the market.

OzTAM (Australia)

Private company under ownership of three main commercial networks in Australia that operates a MOC TAM data service. Responsible for the management and marketing of the metropolitan database (Sydney, Melbourne, Brisbane, Adelaide, Perth) and the national subscription television database.


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P2P (Peer-to-peer)

Peer-to-peer/P2P networks are the alternative to central server networks. Instead of all members feeding of a central server that responds to user requests, P2P networks use the connectivity between participants in the network to handle traffic, whereby requests are handled across the total pool of participants, each of whom contributes to the total computing power, storage space and bandwidth of the network. An important advantage is that the capacity of P2P networks increases as they add members. This is in sharp contrast to client-server networks, where additional customers will cause lower transfer speeds. For content distributors, the appeal of P2P networking is that it reduces central overheads. (see also File sharing)


Method of telecommunications aimed at optimising bandwidth efficiency, whereby multiple users share the same transmission channels and only transmit data when they have data to send, as opposed to establishing a dedicated link (Circuit Switched Data (CSD)).

Page (Internet)

Document with a unique URL that comprises a set of files, which contain any combination of text, images, video and audio materials.

Page traffic

Volume of users who access a given web page, which can be measured either by the number of different users or by the number of click impressions.


Patented method employed by the Google search engine for creating a pecking order in terms of likely importance/relevance among search results on the Internet.


Most widespread global technical broadcast standard for analogue TV transmissions.


Representative survey sample from which data is collected over time. Panels may be short term and employ discrete one-off samples (e.g. some diary surveys) or continuous and long term with samples that change over time according to the number of homes that leave the panel and are replaced by new homes. All peoplemeter panels are continuous and long-term.

Panel age (distribution)

Panel household classification according to length of service on the panel.

Panel balance

Conformity of actual panel allocation to the ideal panel allocation for the selected panel control variables.

Panel control

Demographic or other variables used for maintaining the representativeness of the panel sample over time as homes leave the panel and are replaced by new panel homes. The panel controls specify target profiles for each selected panel control variable, which the panel management staff tries to match as closely as possible during initial panel recruitment and replacement. The selected variables may be treated individually or employed in cell-matrix combinations with other variables.

Panel fatigue

Deterioration in quality of panel measurement that may occur as a function of the length of time that households/individuals have belonged to a panel (e.g. possible increased levels of measured nil or uncovered viewing as panel members cooperate less with their button-pressing instructions over time).

Panel maintenance

Panel staff functions of preserving panel balance over time and likewise accuracy of panel classifications and quality of panel response through the exercise of regular and periodic quality control procedures.

Panel member button

Button(s) on a remote control handset for registering viewing by panel members, with each member having his/her own designated button.

Panel turnover

Index of change in the gross panel sample, which is often defined as the number of homes leaving the panel during the course of each year as a percentage of the installed base at the beginning of the year. Panel turnover, may, however, be defined in several ways depending on the account taken of differences in gross panel size at the beginning and end of the interval and of homes that enter and leave the panel within the interval.

Panel weight

Scaling factor used for correcting imbalances in the daily reporting sample with respect to the weighting variables. The weights also contain a "grossing up" factor for projecting from the achieved weighted sample sizes to the population estimates.

Paper diary

Diary where respondents record their viewing in a paper booklet.

Parabolic (dish) antenna

Receiver for collecting and amplifying off-air signals, which is necessary for domestic reception of satellite TV transmissions. Amplification is achieved through the parabolic shape of the receiving surface, which reflects the incoming signals on to a single point. Hence, the larger the diameter of the parabolic signal the stronger the signal reception.

Parallel run

Side by side running of two different TAM systems for comparison and control purposes. Parallel runs are common when there is a change of contractor in JIC or MOC controlled TAM systems, the objectives being to assess the differences between the new and old TAM, make any necessary adjustments to the new system and assist continuity in the use of the viewing data for programming and advertising purposes.

Parental control

Options included in many digital television, Internet and computer game services, that let parents control exposure of their children to the content being delivered.

Passive sensing

Form of peoplemeter measurement that dispenses with active participation from panel members in favour of alternative "passive sensing" methods of individual identification (e.g. image recognition, thermal sensing, etc.). Various passive sensing methods have been tested. None has been successfully implemented so far and all current peoplemeter TAM systems employ active peoplemeter measurement. This could change in the future, although the successful implementation of passive sensing methods will need to address concerns over respondent privacy as well as technical issues of accurate person identification.

Pay cable

Mini-pay or premium subscription channels/services offered to basic cable subscribers for an additional fee (e.g. HBO). Term mainly used in North America.

Pay to basic ratio

Ratio of the number of premium TV service subscriptions (which may be more than one in any given household), to the total number of basic cable TV subscriptions.


Broadband payment method where the customer pays for the bandwidth consumed.


Form of PPV where the user pays for a video or audio download to the PC.

Pay-per-impression (Online)

Pricing model in which advertisers pay according to the number of ad impressions.

Pay-per-lead (Online)

Pricing model in which advertisers pay an agreed charge for each sales lead generated.

Pay-per-sale (Online)

Pricing model in which advertisers pay an agreed charge for each sales transaction generated directly by their advertising.


(1)    General term for all subscription TV and on-demand TV services. (2) Pay-TV is often used to refer more specifically to premium pay-TV channels such as Canal+, HBO, Premiere or Telepiu. In many countries (e.g. Benelux, German-speaking or Nordic countries, Canada, USA, etc.) where basic cable services are treated as a semi-public or near semi-public utility the term "pay" is usually reserved for mini-pay and premium pay TV services.

PC VOD (PC video-on-demand)

VOD services delivered to the PC rather than the TV.


TV services delivered to the PC, as opposed to TV services delivered to the TV screen.

PDA (Personal digital assistant)

A handheld device that combines computing, telephone/fax, Internet and networking features, including web browser and personal organiser. In contrast to PCs most early PDAs used a stylus rather than keyboard for input and incorporated hand-writing recognition features. Today, PDAs are available in stylus or keyboard versions and some employ voice recognition features.

PDC (Programme delivery control code)

Unique code inserted by programming source (e.g. TV channel) in TV signal transmission as a means of identification and used to control video recording functions, with the PDC data telling the recorder when a particular programme starts.


(see also Primetime)

Penetration (medium/channel)

The percentage of people (or homes) within a defined universe that are physically able to be exposed to a medium/receive a particular TV channel.


Generic name for the electronic measurement system which monitors the channel that a TV set is tuned to and the individuals present in the room while the TV set is switched on. Individual demographics are measured through a complimentary specialised remote control.

Peoplemeter measurement

General methodology for collecting TAM data by means of a household panel sample equipped with a dual metering system that registers (a) TV set status (i.e. which channel is being tuned to) and (b) viewer presence. Peoplemeter TAM research is currently restricted to measuring in-home audiences with meters attached to each TV set. Introduced commercially during the mid eighties, peoplemeter measurement now predominates over all other TAM methodologies throughout the world. Its key advantages for the advertising community are that it offers highly detailed (minute by minute or even second by second) continuous audience measurement for 24 hours a day and 365 days a year, and is impartial, being free from bias compared with the interview and diary-based recall methodologies.

Performance pricing model (Internet)

Pricing model for online advertising, where the client pays a fee according to agreed performance criteria, such as percentage of online revenues.


Most commonly used in computing, but also used in television, to refer to additional hardware items (e.g. scanners, printers, etc.) that can be bolted on to the main display device.

Permanent downloads

Downloads that users can keep as long as they choose and do not self-delete after the expiry of a certain time interval.

Persistence threshold

Minimum uninterrupted interval required before a meter records a change of either TV set status (TV persistence threshold) or viewer presence (viewer persistence threshold). In the case of TV set status, the main purpose of persistence thresholds is to reduce data loads significantly by cutting out very short viewing statements (e.g. bouts of zapping). Until a permanent change of channel is recorded, the meter will continue to record the most recent channel/set use as if no change(s) had taken place. This entails the assumption that consequent errors of attribution are balanced across channels.

Persistent content

Content that is stored digitally on a set-top box disc, PC, DVD, CD or other medium.

Personal meters

Portable metering devices that permit the measurement of an individual's overall exposure to Radio and TV (and possibly print media) both inside and outside the home. Designed to be worn or carried by selected individuals, personal meters can potentially capture viewing/listening in all types of out of home locations. The channel/station identification technique may be based on either audio comparison or recognition of a broadcaster code.

Personal TV

PVR or other timeshift TV services that allow personalised media consumption.

Personalised media consumption

Generic term for the ability of consumers to access, play, pause, fast forward, rewind, store and transfer video content at a time and in a place that suits them and is independent of any broadcast schedule. (see also TV Anytime, TV Anywhere)

Picture in picture

TV display in which one picture is embedded in another picture.

Picture matching

Technique of signal identification in which the meter collects sample visual data from the images displayed on the TV screen, which it matches against an array of known signals from a central reference source in order to establish the identity of the measured signals.


Abbreviation for “picture element”, the Pixel is the smallest single component of a graphic image; the term being commonly used in relation to television scanning, computer displays and digital cameras. The density of Pixels is often used as a measure of image resolution.

Placeshifting (as in viewing)

The viewing of programmes delivered to a device in a separate location by means of a router or other call-up technology from a distant location (e.g. Slingbox).

Plasma display

Electronic flat screen display, which comprises many tiny cells sandwiched between two glass sheets. The cells contain neon and xenon gasses, which emit phosphors when electrically charged. Plasma technology is widely used for large TV screens. (see also Large-screen television technology)


(1) Physical one- or two-way communications pathway (e.g. satellite, cable, terrestrial, DSL) for delivering audiovisual content to end users. see Distribution platform. (2) Marketed TV service over a particular distribution platform that consists of many packaged subscription and/or free-to-view TV channels and other services. see Distribution platform. (3) Signal processing unit (e.g. set-top box) responsible for the decoding, conversion and selection of TV channels and other applications for on-screen display. It is possible for more than one platform operator or other TV channel provider to share the same platform (i.e. set-top box) with the assistance of computer programmes that allow for compatibility of different conditional access systems, although most platform operators operate solely with their own proprietary conditional access systems. (see also Distribution platform)

Platform operator

Company (usually a pay-TV operator) responsible for delivering television and other services over a specified distribution platform(s).


Final stage of preparing and delivering a broadcast signal to a transmission operator for transmission over a broadcast network.


Series of console and hand-held game devices developed by Sony that has become universally popular spread widely throughout the world. Current models may include DVD play and record facilities.


Peripheral devices that can be added to other main devices (e.g. TV sets, PCs) simply by plugging in and without the requirement of reconfiguration by the user.

PMP (Portable media player)

Handheld hard disc or flash memory device for storing / playing files in one or more formats.


US term referring to within programme breaks. (see also Within programme break)


Is a series of digital-media files which are distributed over the Internet using syndication feeds for playback on portable media players and computers. The term podcast, like broadcast, can refer either to the series of content itself or to the method by which it is syndicated; the latter is also called podcasting.

Polled sample

In production meter sample that has been successfully polled by the central processing base of the data supplier and is available for inclusion in the net daily reporting sample.


Procedure for collecting data from meter panel homes, usually by means of a telephone call from the central processing base of the data supplier, which downloads in the early hours of the morning meter data from the previous broadcast day(s) via a modem connection with the central meter data storage unit in the home. Alternative cellular radio or one-way connections methods may be used in order to collect data from non-telephone households and are becoming increasingly common as an alternative to the standard fixed line modem connections. At the same time, polling takes place in a few systems via telephone calls from the household to the central processing base of the data supplier rather than from the data supplier to the home.


Pollux is proprietary software of AGB Nielsen Media Research. The Pollux System is a compact software package to collect, validate, weight and calculate television audience data. Audience events are collected by peoplemeters positioned in participating families' houses and connected to their television sets and telephones.

Pop-up ad/Pop-up (Online)

Online advertisements which automatically "pop up" in a new window when Internet users click on a banner ad or go to a new web page. They generally attract higher click rates than standard banner ads. Pop-up ads which load between two Internet pages are known as interstitials.

Portable media devices

Any portable device with on-screen display (e.g. PDA, laptop, iPod, mobile handset) that can be used for playing received and/or stored video and audio content.


Web site which offers users a range of content and services, often including some kind of directory of search functionality and acting as a gateway to the Internet or a sub-set of it. The portal will typically provide a range of services, including a directory of web sites, homepage space, e-mail, chat or message boards and a variety of other information (news, sports news, etc.).

Position in break

Refers to the running order of a commercial break and where a specific advertisement fell within that e.g. 2/8.

Post (campaign) evaluation

Evaluation of a media schedule at the end of a campaign with audience delivery data in the case of TV advertising.

Post campaign analysis software

Software for analysing and evaluating the audience delivery of a campaign/schedule of advertising spots.


Online video advertising where the advertising commercial plays after the content video play.


The number of people who make up the total population of a selected demographic according to the most recent Census data.

PPC (Pay per click) (Online)

Online advertising purchase where webmasters (i.e. web site operators) display clickable links from advertisers in return for a charge per click. This method is widely in search advertising. Advertisers bid for keywords, with their ads displayed on the results pages generated by searches using those keywords. The more advertisers bid per click in relation to other advertisers the higher up their ads appear on the results pages.

PPM (Portable peoplemeter)

Peoplemeter carried by the survey participant. The PPM was originally developed to measure radio listenership, There is an ongoing debate as how successfully it may also be used for purposes of measuring television viewing. (see also Personal meters)

PPPI (Indonesia)

Persatuan Perusahaan Periklanan Indonesia: An association whose members are advertising agencies in Indonesia.

PPT (Pay-per-title)

Form of PPV for on-demand programming where the user pays for a specific title.

PPV (Pay-per-view)

Programming (usually special live events or newly released films), which viewers must request and pay for in order to view. PPV film services are usually offered in staggered rotation on a group of channels as a form of NVOD (Near video-on-demand).

Pre-defined sample

Pre-designated interview or self-completion questionnaire sample. The pre-defined list of names or addresses may be drawn from a sampling frame or determined by a specific sample selection procedure (e.g. random route or random telephone dialling).


The displacement of an advertising spot in a commercial break by another advertising spot for which a higher price has been bid or when an advertising spot in a commercial break is re-assigned to another programme by the TV station.

Premium channel

Subscription pay-TV channel offered on its own or in small package of channels (e.g. group of premium sports channels), and charged for at an appreciably higher price than other, basic TV channels.

Pre-recorded (video) cassette viewing

Viewing of pre-recorded video cassettes as opposed to timeshift viewing of recorded video cassettes.


Online video advertising where the advertising commercial plays before the content video play.

Price categories

Term used in AGB Nielsen Media Research's TV Events for commercial spots rate card classification based on TV station, type of programme, day of week and dayparts. Advertisement appearances falling into the same category apply the same rules for the price attribution.


Evening daypart associated with largest audiences, generally between 19.00 and 23.00, though precise times may vary slightly by country.

Probability sample

Sample of households/individuals selected on the basis of known probabilities. In the case of simple random sampling, the probabilities are presumed to be equal. By contrast, disproportional sampling involves the deliberate over-/under-sampling of selected variables (e.g. region, telephone ownership), which are later corrected through weighting. The main alternative to probability sampling is quota sampling.

Processed viewing statements

Processed individual viewing statements after editing, validation and conversion of raw meter records into basic units for calculating ratings and reach, as per the algorithms for assigning ratings. (see also Individual viewing statements)

Product placement

Paid for placement of an advertiser's product within a programme.

Product typology

A classification of advertisement items based on distinctive types created according to the local market or international standards; typologies are useful as measures for commercial campaigns systematisation and comparison.

Profile (Adhesion)

The composition of a channel/programme audience, as defined by the proportionate contribution of different demographic categories against one or more variables, such as age and sex (e.g. a channel profile of 26% for Adults 15-34 means that 26% of the total audience for that channel was aged 15-34).

Programme (release) window

Term used in programme rights discussions concerning feature films, TV entertainment series and occasionally other programming. The window refers to a hierarchical sequence of distribution outlets, which are arranged in descending order of the revenues per viewer that they can generate; e.g. feature films made available successively via cinema, video/DVD, PPV, pay-TV and finally free-to-air broadcast release. The window is the period when the programming is first made available in one distribution outlet in the chain of release windows before being made available to the next distribution outlet in the chain.

Programme barter

Offer of programming to a TV station by an advertiser or programme supplier in exchange for commercial airtime.

Programme genre

The classification of programmes by type; e.g. Sport, drama, chat show etc.

Programme loyalty

Measure of constant programme audience across a series of episodes. Numerous different operational definitions may be used to define programme loyalty.

Programme re-run

A term used for a programme which had been broadcast/aired before and is broadcasted again for the 2nd, 3rd, etc. time.

Programme schedule

Sequence of programmes scheduled for transmission over a given period (e.g. day, week) that is released in advance in print or electronic form.

Programme secondary description

Optional description including additional information of TV programmes (e.g. episode information for TV Series).

Programme sponsorship

Promotion in which advertiser pays for an association with a TV programme or series of programmes. In return for his payment, the advertiser is granted sponsor accreditation, which may take several forms subject to international and national regulations (e.g. accreditation in programme guides, billboards at the beginning/end of the programme, break, bumpers, product placement, sponsor mentions within the programmes as well as outdoor advertising and billboards featuring the sponsors logo in the case of broadcast live events). Programme sponsorship deals are often linked with advertising deals in the surrounding commercial breaks.

Programme syndication

Programming distributed to a group of independent regional/local TV stations. The programming may be broadcast as a network transmission or broadcast at different times on different stations, which may or may not belong to a single network group.

Programme typology

(see also Programme genre)

Programme, break and spot database

By recording the broadcast of each channel, the programme, break and spot database is built ready for integration with the viewing data. (see also TV Events system)

Programme/viewing analysis software

Software for analysing viewing to programmes and general audience patterns, including audience shifts/flows between different TV channels, constancy of viewing habits, etc.

Progressive scanning

Method of storing, transmitting or displaying moving visual images in which all the horizontal lines in each frame are scanned in sequence. Progressive scanning is used in digital TV sets and computer screens and displays. It contrasts with interlaced scanning used in traditional TV formats PAL, NTSC and SECAM, which display lines in two phases. The first phase shows all the odd numbered lines, while the second displays all the even numbered lines. To the human eye these appear as a single image.

Promo/Station promo

Non-paid for promotional message by TV stations aimed at attracting audiences to their programmes.

Promotional clutter

Sum total of advertising clutter and additional clutter in the form of sponsorship credits and station promos. (see also Advertising clutter)

Prompt payment discount

Discount on airtime costs for early payment within a negotiated time period.

Proprietary software

Analysis software that is the exclusive property of an organisation and sold or licensed to other users.

PSTN (Public switched telephone network)

World network of public telephone networks using circuit-switched telephone technology, as opposed to the IP-based packet-switched technologies used over the Internet. Formerly restricted to fixed line analogue signals, PSTNs are now almost entirely digital and include mobile as well as fixed line telephones.

PSU (Primary sampling unit)

Sampling point from which one or more survey interviews are taken. Face-to-face interview procedures invariably entail some clustering of interviews at selected PSUs (e.g. building-blocks, local postal area codes, electoral districts, etc.). By contrast, telephone and postal surveys usually have only one interview per PSU.

Public service broadcaster

Non-profit organisation responsible for one or more broadcast TV/radio channels/networks, which is publicly or state owned and obliged to fulfil various public service duties as laid down by the government or by other national public broadcast authority. Many public service broadcasters are part or wholly funded by licence fees or other public subsidy, but many also carry advertising and a few offer subscription-based services (e.g. NHK satellite subscription channels in Japan).

Public service remit

Public service obligations which a TV broadcaster must satisfy as a condition of its public service charter or its broadcast licence.

Pull mode

The delivery method in which a subscriber demands and receives data from the provider.

Push mode

The delivery method where the service provider transmits on a fixed, predictable schedule, or in response to an event such as the updating of data in the subscriber's database. Push mode applications include downloaded VOD services to subscriber PVRs.

Push VOD (Video on Demand)

This is a technique used by a number of broadcasters on systems that lack the interactivity to provide true VOD, to simulate a true VOD system. A push VOD system uses a PVR to automatically record a selection of programming, often transmitted in spare capacity overnight. Users can then watch the downloaded programming at times of their choosing. As content occupies space on the PVR hard drive, downloaded content is usually deleted after a week to make way for new programmes. The limited space on a typical PVR hard drive means that the flexibility and selection of programmes available on such systems is more restricted than true VOD systems. (see also VOD (Video on demand), PVR (Personal video recorder))

Push-button peoplemeter measurement

Push-button refers to the buttons/pads on remote control handsets in peoplemeter measurement, that are used for registering viewer presence and for fulfilling selected other functions, such as collecting guest age and sex demographic details or signalling that the panel home is absent on holiday. (see also Active peoplemeter measurement)

PUT (People using TV)

Term mainly used in the USA to denote average percentage of People using TV across all channels within a set time period. (see also HUT (Homes using TV))

PVR (Personal video recorder)

A device, also called Digital video recorder (DVR), which uses a hard drive to record and store digital video content. An important feature of the PVR it allows viewers to pause, fast-forward and rewind live programmes. Some PVR appliances also have the capability to suggest programmes for users by recognising their viewing behaviour.


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QoS (Quality of Service)

Concept of grade of service applied to telephony and broadband traffic, which may be partly assessed in terms of subscriber feedback, but with the advent of digital networks is increasingly measured in terms of engineering parameters.

Quadruple (quad) play

The combination of broadband Internet access, voice telephony, television and mobile services

Quality control procedures

Systematic and periodic procedures employed by panel management for purposes of checking the quality of data output.

QuickTime (player)

Technology developed by Apple Computer for handling a variety of multimedia formats. The QuickTime Player is freely downloadable from Apple's web site.

Quota sample

Alternative to probability sample whereby a sample is selected according to demographic or other quotas and without known probabilities of selection.


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Radio frequency

Portion of electromagnetic wave spectrum used for audiovisual transmissions that is located above the audio and below the infrared frequencies.

Random combination

A mathematical formula for estimating the reach of two or more media.

Random route

Method of face-to-face interview selection, whereby the interviewer follows a set random procedures for contacting households/individuals in a sample, beginning with a set starting point within the designated PSU.

Random sample

A sample in which every element in the population has an equal chance of being selected.

RASP (Random access stored programme)

Computing technology used in television that inserts index points in encrypted content, so that it can be easily accessed with video trick modes without sequential decryption.

Rate attribution

Rate attribution refers to the price assignment for the commercial events in the AGB Nielsen Media Research's TV Events system.

Rate card

A price list for advertising time and/or space.

Rate card adjusted impact delivery

Measure of commercial impacts that has been adjusted to a unit interval (standard 30 second spot length), but taking into account different price levels. (see also Impact weights)

Rate cards

Rate cards are tables containing prices for the associated price categories available from a broadcaster for a given period of time. They are inserted and updated based on the information provided by the TV station.

Rating (TV)

The average percentage of a given population group watching a TV channel/programme across a set time interval. The concept of rating is generally restricted to TV, but may also be used for other media. One rating point equals 1 percentage. (see also GRP (Gross rating point))

Raw data

Polled meter statements prior to data processing and editing/validation.

Reach (or cover/cume)

The cumulative percentage or total (usually expressed in thousands) of a population that has been counted as viewers at least once during a specified interval. Examples of commonly used reach measures are TV channel daily/weekly/monthly reach, advertising campaign reach, programme reach/ programme series reach, daypart reach and so on. Commonly used synonyms are Cume and Cover.


iMedia player, created by RealNetworks, that plays a number of multimedia formats including MP3, MPEG-4, QuickTime, and Windows Media formats as well as multiple versions of proprietary RealAudio and RealVideo codecs.


A payment to the advertiser by a medium when the advertising schedule does not satisfy the contractual commitments originally agreed to and the advertising schedule earns a lower rate.

Reception quality

The quality of TV signal received in the home.

Recruitment date

Date when a home is recruited on to a panel.

Recruitment survey

Survey other than the ES conducted for the purpose of recruiting homes on to the panel.

Reduced screen viewing

Viewing which takes place where the main broadcast channel is shown in reduced size within a screen that has other content.

Reference signal

Source used for comparisons in picture and audio matching methods for signal identification.

Regional TAM (Australia)

Private company under ownership of the five FTA regional commercial networks in Australia that operates a MOC TAM data service. Regional TAM is responsible for managing the Regional TAM contract that is collected and marketed by AGB Nielsen Media Research Australia.

Regional TV

TV channels targeted at geographically defined regions within a country.

Regular visitor

Person who is a regular guest viewer and may be assigned his/her own button in order to avoid the more cumbersome, time-consuming process of recording guest age and sex at the start of every viewing session. Though treated in exactly the same way as panel members with respect to task instructions, regular visitors are still classified as guests in the processed viewing data output.

Remote control handset / unit

(1) Remote device for changing channels or activating other functions (e.g. playing DVDs) on the TV set. (2) Remote control handset employed for registering viewer presence in TAM research. Often referred to as push-button handsets.

Reporting homes

The number of panel homes that contribute to the daily ratings. Where failure to meet quality control standards or communications related problems occur, such installed homes are eliminated from the reporting panel. Also known as In-tab homes.

Reporting sample

Final validated sample of eligible survey respondents from data are reported.

Reporting universe

Demographically or otherwise classified population for reporting viewing data, which is specifically weighted for so as to conform to a constant population estimate.


The density of a TV image, that is determined by the number of Pixels in the screen display. High definition TV signals are so called because they have higher resolution than Standard definition signals.

Respondent level viewing data

Same as Disaggregated viewing data - Processed viewing data held at the level of individual respondents.

Response bias

Bias in survey data due to measurement methods (e.g. recall bias in diary or day after recall TAM research, or panel fatigue in peoplemeter measurement).

Return Path (or Upstream, or Reverse Path)

A data link that goes from a digital television system subscriber back to the system head-end. For a cable system, this may be the same cable. For a satellite or IPTV system, it may be a telephone landline or GPRS link.

Return Path Data

Any information sent via a Return Path, including system information such as subscription and pay per view requests, also user interactivity, and potentially research information on audience size by channel.

Revenue sharing

Agreement between TV stations and content providers, including production houses, to split revenues earned by programme/s.

Review buffer

A buffer on a hard disc that automatically stores a configurable number of minutes of any programme that is being viewed live. This facility is necessary for permitting live pause and rewind functionality on PVRs and other timeshift devices.

RGU (Revenue generating unit)

Metric used by cable operators and broadband ISPs offering a selection of services (e.g. triple play), to denote the total number of paid for services being taken across the customer base. The customer base may also be categorised according to the number of RGUs taken by each customer.

Rich media (Online)

Online advertising with which visitors to a web site can interact in a web page format.

RIM (Random iterative method) weighting

Method of weighting that puts selected non-interlocking and grouped interlocking variables in isolation through an iterative sequence of weighting adjustments. The sequence adjusts for each rim in turn and then repeats itself as many times as is required in order to obtain a convergence, in which the sum of the weighted rims matches the target population estimates, or is as close as it is possible to achieve.


Process of copying digital or analogue content from one form to another (e.g. transferring CD or DVD content to a hard-disc or vice versa).


A programme or commercial scheduling device used by broadcast networks to increase or maximise reach at a given time (e.g. Scheduling a commercial on all local market stations at 9:00 p.m.).

ROI (Return on investment)

Commercial returns (usually revenues) generated in response to advertising investments in the media. ROI estimates may involve a number of assumptions.

Rolling sample

Sample for which data is reported at regular intervals for time periods that overlap with preceding time periods (e.g. figures for last 12-months reported quarterly).


A marketing procedure where advertising is progressively expanded into more geographic areas over time.

ROS (Run of schedule)

Procedure for transmitting advertising spots, in which the TV station has the discretion to transmit a given spot at any point in the advertising schedule, but within the terms of the negotiated guarantees of audience delivery.

RR (Response rate)

Index of survey response in surveys employing interview or self-completion questionnaires. The RR is typically defined as the total number of successfully completed interviews expressed as a percentage of the total number of addresses/individuals approached during a survey: the main reasons for non-response being absences and refusals. Precise operational definitions are highly variable, though.

RSS (Really simple syndication)

Software system making use of feed reader or aggregator programmes that facilitates subscriber access to their favourite web sites by helping to check feeds and pick out materials of interest to them.

RTSP (Real time streaming protocol)

Video streaming protocol developed by the IETF that allows client users to control the streaming server by using VCR-like commands such as “play” and “pause”. RTPS is employed in a number of streaming media systems (e.g. RealPlayer, VideoLan, MPlayer, Window Media Player, QuickTimer etc).

Run of station

(see also ROS (Run of schedule))


Period (usually from two to seven days) when a newly installed home is under observation before it enters the panel sample. The home is placed in directory and polled, but withheld from production in the net daily reporting sample.

Running text (CG Crawl)

Character Generator Crawl: promo with moving text during a programme.


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SAARF (South Africa)

South African Advertising Research Foundation: Multimedia joint industry organisation responsible for TAM data provision in South Africa.

Sales house

Separate organisation or department within a TV station responsible for selling commercial airtime.


One or more elements (individuals or households) selected from a universe to represent that universe.

Sample bias

Bias due to lack of representativeness within a sample. It is a wholly distinct concept from sample error. Unlike the latter, sample bias cannot be calculated statistically, but can only be established empirically by comparing two or more samples with different known composition. Latent bias is often used to refer to potential unknown or hidden biases in the data which cannot be assessed.

Sample composition

Sample structure or profile, as determined by the full set of sample classification variables (e.g. Age; Sex; Household size; Number of TV sets in the home; etc.).

Sample dispersion

Geographic dispersion of sample. Dispersion is a function of the clustering of PSUs or number of interviews per PSU. Peoplemeter panels usually apply rules for improving dispersion by limiting the number of homes recruited per PSU and/or restricting the proximity of panel homes with one another.

Sample error

Statistical measure of the possible deviation of a sample estimate from the true population value, assuming the sample to be representative of the population from which it has been drawn. The sample error is normally expressed as a margin of difference either side of the reported value within specified confidence limits (i.e. "there is an x% probability that the true population value lies within y units either side of the sample estimate"). Sample error is wholly distinct and not to be confused with sample bias, for which no parametric statistical assumptions can be made.

Sample size

The number of households or individuals selected for a research sample.

Sample stratification

(see also Stratification)

Sampling frame

Source of addresses/household telephone numbers from which a pre-selected probability sample of identified individuals or households is drawn for interview. Usually the sampling frame is external (e.g. official population register of households/ individuals, telephone lists, lists of postal addresses, electoral lists). Where such pre-existing sources do not exist, data suppliers may create their own sampling frames by means of conducting a micro-census or by carrying out a prior enumeration study of households in areas selected for the establishment survey fieldwork. Alternatively, they may work without a sampling frame, but in that case it would not be completely random.

Sampling interval

Fixed interval with randomly chosen starting point for selecting items on a list with equal (or known other) probability of inclusion in the survey sample. The term also applies to the selection of addresses at a PSU, although the term step function is also commonly used.

Sampling point

(see also PSU (Primary sampling unit))

Satellite reception

Direct reception of satellite TV signals by means of an individual (DTH) or collective (SMATV) satellite dish receiver. Operational definitions employed by TAM systems may differ slightly (e.g. inclusion of SMATV under cable reception) depending on structural distinctions that are found most relevant in the local marketplace.

Satellite station

A broadcast station that rebroadcasts the transmission of another station (generally operating in a nearby market) to an area that cannot otherwise be serviced by that station.

Satellite TV

General term for all TV channels and other services that are transmitted via satellite and can be accessed via DTH or SMATV reception.


A plug and socket with 21 pins. Used to link audiovisual equipment including set-top boxes.


Purchasing commercial time in broadcast media in many different programmes. Also refers to the purchasing of network TV time, which is not purchased during an "upfront" media buy.


Process of interfering with a signal so that a decoder is needed in order to receive it for on-screen display. Scrambling is commonly used by free-to-air TV cable and satellite channels in order to restrict cross-border overspill and protect against infringements of their programme copyright agreements.

SDTV (Standard definition television)

Television transmissions with picture resolution that meets accepted industry standards, but offer significantly lower resolution than enhanced television and high definition television (HDTV) services that are becoming steadily more widespread. (see also HDTV (High definition television))

Search engine marketing

Form of Internet marketing that seeks to promote website traffic by increasing their visibility in the search engine results pages.

Search engine/Search service

Internet application which enables users to search for and find material on the world wide web. Mainly used in the context of web searches, search engines typically operate with a list of keywords or phrases that direct users to relevant sites, although natural language search engines are being developed.

Search list

List of web sites on results pages of an Internet search. The sites may be ranked according to variable criteria of importance and relevance or, in the case of paid-listings, on how much advertisers have paid. (see also Search listing)

Search listing

Reference to a web site on the results page of an Internet search, typically containing some contextual information about the web site (e.g. sentence or phrase(s) containing the embedded search word(s)). (see also Search list)


International technical broadcast standard for analogue TV transmissions that is employed in France and some other countries.

Server (video)

Computer system with large video and audio storage capacity (typically in order of 500 Gb for broadcast services) that is connected to a network of client users and intended for transmission and distant access (e.g. on-demand video programming).

Server initiated ad impression.

(see also Ad impression (Online))

Session (Online)

(1) Sequence of Actions by one user at one web site. (2) Series of actions by a user that can be tracked across successive visits.

Setmeter measurement

General methodology for collecting household TV viewing data using meters that only collect information on set/equipment/ channel use: i.e. do not collect any information on individual viewing.

Sets in use

Previously referred to as the number of TV sets in use (turned on) at a given time. Currently referred to as HUT. (see also HUT (Homes using TV))

Set-top box data

Digital set-top boxes support communication between providers and their subscribers, and vice versa. This communication link back to the provider also gives that provider the ability to collect information on all activity taking place within the set-top box, including programmes tuned or services selected. This information identifies only commands given to/actions taken by the set-top box actions, and does not provide information on the person or persons viewing.

Set-top box interface

Interface between the meter and the set-top box.

Share of audience

Viewing of a specified population, whether households or individuals, that is tuned to a particular programme or station during a given time interval, and expressed as a percentage of the total TV audience during that interval.

Share of market

Percentage of total category volume sales accounted for by a brand.


Multiplatform freeware audio streaming technology, developed by Nullsoft. SHOUTcast uses MP3 or AAC encoding of audio content and HTTP (though multicast can be used) as the transport protocol to broadcast web radio, also known as Internet radio. The most common use of SHOUTcast is for Internet broadcasting. Using SHOUTcast it is possible to set up an Internet broadcasting station cheaply, allowing hobbyists to set up their own networks for a fraction of the cost of a traditional AM broadcasting or FM radio station.


A portmanteau of "shuffled broadcast", and refers to programmes or events broadcast across more than one medium, or more than one service on the same medium, with a different events sequence from the one of the originating station.

SI (Service information)

Proprietary information about the applications software in a set-top box, which can be used to facilitate the measurement of non real-time broadcast viewing (e.g. PVR use) and on-demand viewing, but relies on the co-operation of the service provider.

SI Code (Service information code)

A code broadcast by a channel that uniquely identifies that channel and contains additional schedule information that can assist viewers in their choice of programmes (e.g. EPG information, schedule listings for PVR timeshift, etc.).

Signal injection (technology)

Technology of facilitating later signal identification by means of boosting the incoming transmission with a high frequency burst which can be detected by a sensor attached to the TV set.

Signal sampling

Meter collection of visual or audio data samples that are used later in picture and audio matching methods of signal identification.

Signature (also known as spot signature)

The digital fingerprint extracted from a commercial spot that allows its automatic recognition in the future.

SIM (Subscriber identity module)

Smart card placed in the mobile handset that identifies the mobile telephone subscriber and contains additional subscription information. USIM (Universal subscriber identity module) is a variant used by UMTS.


Simultaneous broadcasting of a TV channel or programme on two or more different transmission systems (e.g. TV channels broadcast simultaneously in analogue and digital formats). Also, the simultaneous broadcast of the same programme on two or more different channels. Another application is the transmission of the original language soundtrack of movies or TV series over radio, with the television broadcast having been dubbed into a local language.

Single source data

Two or more sets of data from the same sample. The term is often used in media research to refer to surveys that combine the collection of product/service purchase/consumption patterns with media consumption habits from a single household or individual source.


Proprietary peer-to-peer Voice over IP (VoIP) network. (see also VoIP (Voice over Internet Procotol))

Slave meter

Meter installed on a TV set or other equipment that is "subservient" to another "master" meter in the household, which controls some of its functions (e.g. time synchrony) and collects data from it for temporary storage and delivery to the central processing base of the data supplier during polling.


TV streaming device enabling users to view programming that they receive at home in distant locations, whether on a PC or other device (e.g. 3G mobile handset, PDA, etc.) with a broadband Internet connection. Developed by Sling Media Inc. in California, the Slingbox can be used for connectivity between devices in the home as well as anywhere in the world via the broadband Internet. The Slingbox has the ability to programme PVRs and Set-top Boxes via a separate infrared cable.


The position of a programme or commercial break within a TV programme schedule.

Smart card

A plastic card (the size of a credit card), which is inserted into the set-top box and whose functions are to verify the user's entitlement to access a given TV channel or other service and monitor use. Smart cards are normally used for determining pay-TV access, but may also be required by some free-to-air channels.

Smart/intelligent antenna

System of antenna signal arrays that is able to detect the location and track movements of a signal source. A basic distinction exists between switch beam smart antennas, which select from several available fixed beam patterns, and adaptive array smart antennas, which are steered in the direction of the signal beam.


Any handheld electronic device that combines the functions of a mobile telephone and PDA or other information appliance.

SMATV (Satellite master antenna television system)

MATV system equipped with one or more satellite receivers for picking up additional TV channels via satellite. (see also MATV (Master Antenna Television))

SMS (Short message service)

Text messaging service available on most mobile phones.

SMS (Subscriber management system )

Management system employed by subscription platform operators for handling subscriber payments and queries.

Social network (Online)

Web site, that serves as an online meeting-place, where users are able to connect with friends and make new contacts.

Software house

Third party company developing its own software applications and undertaking TAM data analysis on behalf of licensed users.

Software supplier

Company supplying application software for purposes of programming/advertising analysis.


Defines the condition where the members of a reference target are the focus of an analysis only when they are watching television alone.

SOV (Share of voice)

Percentage of advertising impressions generated by all brands in a category accounted for by a particular brand. SOV also often refers to share of advertising spend in a given medium.


Shortened term for the electromagnetic or radio frequency spectrum, portions of which have been allocated by international agreement for specific classes of application, including radio, broadcast television, mobile TV, etc. Use of the radio frequency spectrum is regulated by national governments as well as subject to international co-ordination agreements aimed at minimising interference between neighbouring territories.


Spill-in is viewing of television broadcast from a different market (e.g., people in San Diego viewing Los Angeles stations). Spill-out is viewing outside the originating TV market (e.g., Los Angeles stations delivering audiences in San Diego).

Split screen

TV screen partitioned so as to allow simultaneous display of two or more video tracks.

Spot purchase

Purchase of TV commercial time on a market-by-market basis as opposed to network (national) purchases. Also commonly used in lieu of "commercial announcement".


Two-dimensional image or animation entered into a larger scene.


Computer software designed to get information from a PC without the user's informed consent. It may used for criminal (e.g. theft of credit card details) or other purposes, including commercial objectives, such as monitoring Internet use in order to assist targeting, or deliver unsolicited advertising. Term is interchangeable with adware and malware.

Squeeze frame

Method of “squeezing” the programme frame in order to make space for an advertisement or promo.


Broadcast of channel output on a secondary channel a fixed time after the original broadcast. The most commonly used time lag is one hour, and such secondary channels are often labelled "+1".

Standard error

Standard deviation of the sample error distribution of sample estimates. 1.96 standard errors denotes the upper and lower bound margins of sample error that correspond with 95% confidence limits. (see also Sample error, Confidence limits)

Station average price

Estimated cost of unit audience delivery on a TV station based on advertising Costs per rating point (CPRs) or advertising Costs per thousand (CPTs or CPMs). SAP is normally calculated with reference to specified time periods (usually calendar months) and selected target audience(s).

Station promo

(see also Promo)

Station relay

(see also TV Pool)

Statistical efficiency value

Index of sample variance, usually expressed as a percentage, which compares the variance of the actual sample with the variance of a simple random sample of the same size. Thus, a statistical efficiency value of 85% means that the measurement accuracy of the weighted reporting sample is the same as the measurement accuracy of a wholly representative unweighted sample that is 0.85 raised to the power 2 (= 0.72) of its size.

STB (Set-top box)

Device that receives, processes, converts and displays incoming TV signals, for display on TV sets. The set-top box may be designed to receive signals in analogue or digital form and from cable, satellite and terrestrial sources.

Step interval

Common term for the fixed sampling interval between addresses selected for interview at chosen PSUs. (see also Sampling interval)


Means of improving the quality of a probability sample by selecting sample elements according to population variables with known distribution profiles in order to determine a proportional or disproportional allocation of the survey sample. Examples of commonly used stratification variables are "region", "type of settlement" and "household size".


The delivery of video or audio content stored in bits which enables it to be played in real time and without viewers having to wait for all the data to arrive.


Scheduling a programme (such as a series) at the same time, every day of the week. This is the opposite of checkerboarding, which is the standard method of scheduling programmes on primetime. (see also Checkerboarding)

Sub-contractor (TAM research)

Research company(ies) sub-contracted by the main data supplier to handle part of the data provision. This practice occurs most often with the ES (Establishment survey).


Very short commercial messages below the threshold of conscious perception that could be inserted in advertising, rules permitting.


TV household or other entity (e.g. hotel) that pays a regular subscription charge in order to receive a specific TV channel or programme service offering a variety of TV channels and other services.

Summer time

(see also DST (Daylight saving time))


User search and sampling behaviour over the Internet lacking a specific goal (akin to channel-hopping with a TV remote control).

Survey coverage area

Area that has been covered in a survey.

Survey frequency

Frequency with which a survey is carried out.

Survey population

Total eligible population belonging to a survey universe.

Survey universe

The total population that is being measured or reported, as defined by a selection of demographic, geographic, housing, equipment and other criteria (e.g. nationality/language/ethnic origin). Within the total universe, TAM services may further designate one or more narrower universes (e.g. cable/satellite, region, etc.) that are controlled for and weighted separately.

SVOD (Subscription video-on-demand)

Any VOD service paid for on a subscription basis.

SVP (Secure video processor)

Hardware-based solution to content protection and authorisation involving an SVP-compliant chip. The SVP may be embedded in a piece of equipment or carried separately (e.g. like a memory stick) and installed when needed. SVP is an open technology specification developed by an alliance of members.

Sync measurement scanning

Channel identification method used when there is no scart (or similar) connection in place and an internal tuner is connected to the same signal source as the household TV. An external pick-up compares sync pulses from the TV set with sync pulses coming from the internal tuner.

Systematic sorting procedure

A systematic objective procedure for organising a sampling frame list of names or addresses for subsequent selection with equal or known probabilities.


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TAC (Australia)

Technical Advisory Committee: Forum comprising representatives from the media industry where technical issues regarding the ratings service are discussed with a focus on continuous improvement.


Widely used acronym for Television Audience Measurement.

TAM system/service

Data supplier system/service for measuring television viewing and delivering TAM data.

Target audience

Core TV audience which an advertiser is aiming to reach; typically specified in terms of sex, age, socio-economic grade and housewife/main shopper categories. In many countries, airtime prices are negotiated with respect to specified target audiences.

TARP (Target audience rating point)

Unit GRP with reference to a specified target audience.

TBG (New Zealand)

New Zealand Television Broadcasters Council: An industry organisation representing the non-competitive interests of the free-to-air broadcasters in New Zealand.

TC (Trusted computing)

Technology developed and promoted by the Trusted Computing Group (TCG). The term is taken from the field of trusted systems and has a specialised meaning. In this technical sense, "trusted" does not necessarily mean the same as "trustworthy" from a user's perspective. Rather, "trusted computing" means that the computer can be trusted by its designers and other software writers not to run unauthorised programmes.


Transactional commerce via interactive advertising, including Internet pages accessed via the TV screen as opposed to the PC or mobile telephone.

TCTA (Thailand)

Thailand Cable TV Association.

TEA (Terminal education age)

Classification variable based on age at which individual completed his/her educational studies.


Omnibus survey conducted over the telephone instead of face-to-face. (see also Omnibus Survey)


The user interface of AGB Nielsen Media Research's TV Events system, it facilitates the workflow of the TV Events production, which includes: Data Entry, Rate Attribution, Cleaning, Export and Programmes/Products tables editing. TelePad is also the interface to ASR recognitions stored in the Grabbers. From TelePad, user can select the reference signatures to be used in the real time ASR recognitions.

TelePad server

The storage of the database of emissions inserted using AGB Nielsen Media Research's TV Events system. In addition, the same machine is storing the audio/video signatures library and the video clips of the spots saved by the user to facilitate the visual recognition of commercial spots.

Telephone interview

General methodology for conducting survey interviews over the telephone.


Broadcast service using several otherwise unused scanning lines (vertical blanking intervals) between frames of TV pictures to transmit information from a central data base to receiving television sets.

Teletext code

Signal code carried by TV channels offering teletext services that provides an additional means of channel identification.

Teletext use

Measured viewing of teletext pages. TAM systems vary greatly in the level of detail with which they measure teletext use and in how they treated it later: in particular, over whether they report it separately or ignore it, assigning all teletext use to the channel carrying it.

Terrestrial analogue only TV home

TV home that is only equipped to receive locally available channels broadcast in analogue via aerial reception. The category is mutually exclusive and exhaustive with Multichannel TV home.

Terrestrial only TV home

Formerly used instead of Terrestrial analogue only TV home when digital terrestrial television did not exist. But with the introduction of digital terrestrial TV services, reference to analogue has become necessary in order to avoid misunderstanding, when that is the intended meaning. Nowadays terrestrial only TV homes means any home that is equipped only to receive analogue and/or digital terrestrial broadcast channels, as distinct from additional cable and satellite channels.

Terrestrial TV

TV channels broadcast terrestrially in analogue or digital and which can be received off-air.

Test market

A market (or markets) chosen for the purpose of conducting a media test.

Text link

Clickable piece of text appearing on a web page that leads to another web page.

TGI (Target group index)

Market interview research that combines questions about media use with product/service consumption habits. The research is aimed at indexing the levels of product/service consumption for a specific media title (e.g. TV channel, radio station, newspaper, magazine etc.) or category.

Thematic channel

TV channel specialising in a particular kind of programming (e.g. showing children's programming, films, sports, weather, news, different kinds of documentary, etc.).

Third party access

Data access by parties other than the primary user group of advertisers, media buyers and media owners.

TIAK (Turkey)

JIC responsible for TAM data provision in Turkey.


Offering of subscription packages of TV channels and other services in a tiered sequence, such that subscribers must first sign up to a basic package before being allowed to subscribe to additional packages at extra cost.

Timeshift recording

Recording of live TV transmissions on video cassette or hard disc for viewing at a later time.

Timeshift viewing

Later viewing of timeshift video recordings of live television transmissions (i.e. Playback of recorded live transmissions).

Token pay-per-View

Pay-per-view in which user entitlement is paid for by a card. The card may be rechargeable.

Tolerance margin

Latitude of acceptance of the deviations of the actual sample allocation from the target sample allocation before attempting corrective action.

Total video playback

Sum of pre-recorded video cassette viewing and timeshift viewing of recorded video cassettes.

Total viewing

(see also Amount of viewing)

Trailing gap

Interval of uncovered viewing at the end of a viewing session.

Transitional ad (Online)

An ad displayed between web pages, also known as an interstitial.

Transmission logs

Exact records (usually electronic) of television channel transmissions, as supplied by the TV channel or by an independent monitoring agency.

Transmission unit

Meter installed in every household that has the function of storing and retrieving the data from the base unit. Polling of the household data is achieved through a phone connection, which downloads the data to the central processing base of the TAM supplier. (see also Master meter)

Transnational TV

TV channels targeted at audiences across two or more countries with limited modification in terms of locally sourced programming and advertising.


Satellite receiver/transmitter unit receives uplink signals, which it amplifies and retransmits as a downlink signal back to earth.

Transport stream

A digital broadcast transmission stream comprising a number of elementary streams (e.g. separate video, audio, and EPG metadata streams for each channel in a multiplex broadcasting system). The basic unit of data in each stream is the packet, which has its own identification tag (PID). The stream is processed in several players. In the case of multiplexed signals, the goal is to achieve de-multiplexing and synchronisation of output with minimal error.

TRCC (Tripartite research company contract)

Form of survey organisation whereby the contracting party delivering TAM data to the market is itself a research company, but with tripartite ownership of media owners, advertisers and advertising agencies/media buyers. The research company/ organisation at the centre of a TRCC contract may sub-contract part or all of the fieldwork to other market research companies.

Trick mode

Pausing, rewinding and fast forwarding live or stored video content.

Triple play

The combination of broadband Internet access, voice telephony and television services.

TRP (Total rating points)

Total GRP delivery over a campaign period. (see also GRP (gross rating point))

TRPs (Target tating points)

(see also TARP (Target audience rating point))

Tuner meter

Meter that identifies channel frequencies by subsuming the functions of the TV set tuner or other receiving equipment (e.g. VCR, satellite dish) that may be used to select channels on the TV screen.

TV Anytime, TV Anywhere

General umbrella term embracing all those technologies and associated devices (e.g. PVR, DVD recorder/players, 3G mobile handsets, Slingbox, media players) and on-demand services that empower users to view any TV programme at any time an in any location they choose.

TV channel

Identity of single TV service transmitting programmes usually on a specific frequency (-ies), but sometimes sharing frequency with other TV channels/services, which transmit on the same frequency at different specified times of the day. The term "TV channel" is almost always used interchangeably with "TV station", though it is more likely to be used when the emphasis is on a single specific service, whereas TV station is most likely to be used when emphasis is placed on the programme service or organisation operating the TV channel.

TV clutter

Another term for advertising or promotional clutter. (see also Advertising clutter, Promotional clutter)

TV Events system

TV Events is the broadcast monitoring system of AGB Nielsen Media Research that offers a complete, highly reliable and easy to use suite of tools for the creation, collection and maintenance of high quality TV events databases.

TV market

Designated geographic reception area or population at which a TV service is targeted for commercial purposes. It is distinct from and may be smaller or greater than the technically defined coverage area. (see also Channel coverage)

TV Pool

A programme that is broadcast/transmitted at exactly the same time simultaneously among two or more TV stations.

TV station

TV channel or organisation operating one or more TV channels. Depending on context, TV station may also cover sales houses that sell television airtime on behalf of one or more TV channels/stations. Although the term TV station is most often used interchangeably with TV channel, the terms can carry different points of emphasis. (see also TV channel)

TVCAB (New Zealand)

Television Commercial Approvals Board: New Zealand is a fully deregulated broadcasting environment. The TVCAB was established by the commercial networks to support self-regulation. The TVCAB views all commercials prior to broadcast to ensure compliance with advertising codes.


TV set with a built in video recorder.

TVIRC (Hong Kong)

Television Research Committee: JIC responsible for TAM data provision in Hong Kong.

TV-M (Finland)

TV Mittaritutkimustoimikunta: JIC responsible for TAM data provision in Finland.

TVM series

Series of Peoplemeters developed by AGB Nielsen Media Research.


Television services delivered over a wired telephony network using DSL technology.

TVR (Television viewer rating)

Term used in place of GRP in the UK and in Ireland.

TVRC (Philippines)

Television Research Committee: JIC responsible for TAM data provision in the Philippines.

TVRO (Television receive only)

Satellite system equipped only to receive signals from, but not to transmit signals to a satellite.

Twisted pair

Early wired electrical transmission system, now superseded by coaxial and fibre-optic technology, formerly employed by cable television systems with low channel carriage capacity for purposes of extending reception of off-air terrestrial signals for a limited number of TV channels.

Type of reception

Method of receiving television pictures (e.g. cable, satellite, terrestrial, etc.). It may also include pay-TV reception, otherwise classified under channel reception.


(see also Programme genre, Product typology)


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UDP (User datagram Protocol)

One of the core protocols of the Internet protocol suite. Using UDP, programmes on networked computers can send short messages sometimes known as datagrams to one another.

UGC (User generated content)

Multimedia content created by users and posted on the Internet for access and consumption by other users. (see also Consumer generated media)

UHF (Ultra high frequency)

Bandwidth reserved by international agreement for television broadcast channels 14-83 on a TV set. UHF has replaced the former VHF bandwidth as the specially reserved portion of spectrum for television broadcasting, although national governments may still choose to allocate VHF bandwidth for TV broadcasts.

Ultra high definition video

Experimental format with a resolution of 7,680 x 4,320 pixels now being proposed by NHK in Japan. The new format is four times as wide and 4 times as high as and offering 16 times the resolution of the existing maximum format for HD, which consists of 1,920 x 1,080 pixels. A particular advantage of the proposed standard is that the height of 4,320 pixels is a lowest common multiple of all NTSC and ATSC TV resolutions, making it possible to scale up pictures from other formats without distortion.

UMTS (Universal mobile telecommunications system)

A 3G mobile phone technology that uses W-CDMA as the underlying standard. W-CDMA is the standard used in Europe.

Uncorrelated viewing

Unidentified viewing measured by picture or audio matching techniques, whereby the data production system is unable to match the meter statements with centrally generated records of the channels being monitored.

Uncovered viewing/ set use

Meter statements indicating that the TV set is switched on, but without any persons registered as present.

Unexpected viewing

Viewing to an unexpected source, as defined by the TAM system.


Sending of information packets to a single destination. Often used to mean streaming content to a single user at a given time.

Unidentified channel viewing

Viewing to an unknown frequency as ascertained by DFM or tuner meters. The frequency is usually presumed to belong to a channel, although it may indicate a separate output source (e.g. video games console).

Unidentified viewer

Persons (not a guest) registered as present in the viewing records, but not found in the records for the panel home.


An audience measurement system developed and produced by Media Instruments (an AGB Nielsen Media Research company) which is based on its proprietary CTS technology and comprises an integrated TAM panel system, including peoplemeters, a full featured polling system and multi-purpose centralised processing software.


(see also Survey universe)


TV signal that is transmitted in the clear and which viewers can receive without the need of a decoder.

Upfront (buy)

Term mainly used in USA, to denote booking of TV commercial airtime well in advance of its due transmission dates (i.e. booking airtime in autumn of one year for the whole of the following year). The practice of advance booking of a substantial proportion of commercial airtime and reserving the rest for tactical buys is common practice in the USA and similar principles apply in many other countries, although precise trading practices vary appreciably across different national commercial airtime markets.


Signal pathway from the earth to the satellite.


Term used widely in interactive TV (iTV terms) to refer to the signal pathway from the home to the service provider (e.g. cable operator). This will usually have lower bandwidth demands than the downstream signal pathway from the service provider to the home.


Transfer speed of data from client to server across a connecting network (e.g. telephone wire). Opposite of Downstream.

USB (Universal serial bus)

Widely used standard for interfacing devices, which was originally designed for PCs, but is now a commonplace feature of TV sets and peripherals.

UTPC (Universal television programme code)

Unique TV transmission code indicating identity of source. (see also AMOL (Automated measurement of line-ups), PDC (Programme delivery control code), VPS (Video programming system) codes)


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Phase of processing in which viewing data is examined for irregularities that indicate actual or possible technical problems or suspected faulty compliance by panellists. In extreme cases, the application of validation criteria leads to the rejection of certain panel homes from the daily reporting samples.

VCR (Video cassette recorder)

Device for recording and playing video cassettes.

VHF (Very high frequency)

Former bandwidth reserved by international agreement for television broadcast channels, but now replaced by UHF. (see also UHF (Ultra high frequency))

Video clip

Short clips in video formats, mostly less than 15 minutes and often much shorter; now heavily used over the Internet (e.g. for news, sports, programme trailer and vblogs) and in fast growing use as mobile TV downloads.

Video playback

(see also Total video playback)

Video timeshift

(see also Timeshift viewing)

Video-capable handsets

Mobile handsets that can receive and display video images.

Viewers per 1,000 households

The number of people within a specific population group tuned to a TV programme per 1,000 receiving households.

Viewing behaviour analysis software

Software for analysing viewing of programmes and general audience patterns, including audience shifts/flows between different TV channels, constancy of viewing habits, etc.

Viewing card

(see also Smart card)

Viral marketing

(1) Any online advertising that propagates itself. (2) Any online advertising/marketing that spreads by passing from one Internet user to another.

Virtual LAN/VLAN

Wireless LAN connecting a group of hosts that can communicate with one another regardless of their physical location. VLANs may be defined by a set of switches.

Virtual world

Computer-based simulated environment in which users interact with avatars as if in the real world. Virtual worlds have attracted massive popularity and feature in many computer games, but their applications may also include teleconferencing and chat-rooms.

VOD (Video-on-Demand)

Programme service where the content is not broadcast, but stored in a library, which users can access on-demand. Typical VOD content offerings include recently aired television programmes (as in catch-up TV), popular series, selected categories of thematic programming (e.g. music, children’s programmes), and movies. There are three models of VOD content - free VOD, Pay-per-title, where the user pays an individual fee per programme or event, and subscription VOD, where the user pays a flat fee for access.

VoIP (Voice over Internet Protocol)

Voice telephony services delivered over network infrastructures using the Internet Protocol.

Volume discount

Price discount offered to advertisers who purchase a specified volume of advertising from the TV station. Volume discount deals may be negotiated in various ways. Common examples are volume discounts based on (a) total TV advertising spend on TV station by advertiser, (b) proportion of TV advertising budget allocated to the TV station, (c) year on year increase in total allocated advertising budget, or (d) total volume purchased by the media buyer acting on behalf of the advertiser.

VPN (Virtual private network)

A private communications network often used within a company, or by several companies or organisations, to communicate confidentially over a publicly accessible network.

VPS (Video programming system) code

Programme code identifying source of transmission.

VSS (Video signal scanner)

Variant of picture matching technology consisting of an internal TV tuner connected to the same source as the TV set, which scans sequentially through a pre-programmed list of channels and compares them with the video signal displayed on the TV screen until a match is found.


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Walled garden

Restricted group of interactive Internet pages that are offered by an intermediary service provider (e.g. satellite platform operator offering its subscribers a home shopping mall from a database of selected Internet pages, which are broadcasted in digital for access on the TV screen).

WAP (Wireless application protocol)

Open international standard for mobile Internet access for wireless devices such as PDAs and mobile telephones. Examples of WAP technology include the ability to receive news/sports clips and audio downloads as well as to send e-mails.

WAPI (Web aided personal interviewing)

(see also CAWI (Computer aided web interview))

W-CDMA (Wireless code division multiple access)

A 3G mobile telecommunications protocol that uses the direct sequence CDMA signal method in order to achieve faster transmission rates and support more users.


A level of frequency, or a point in time, when an advertising message loses its ability to effectively communicate.

Web 1.0

The world before web 2.0. The appellation Web 1.0 came as an afterthought after the coining of Web 2.0; recalling days of slow-speed narrowband 50K dial-up connections and where most sites offered no interactive facilities.

Web 2.0

Label for the trend in Internet consumption over the past few years to enhance user creativity, information sharing and collaboration, and thereby the creation of web-based. Characteristic features include social networking, blogs, folksonomies (collaborative/social tagging) and wikis.

Web 3.0

While Web 2.0 describes the recent evolution of the Internet medium, Web 3.0 has to do with visions and speculation about how web use will develop in the future; a core concept being the “semantic web”.

Web banner

(see also Banner ad)

Web browser

Software application that allows users to access and interact with content at websites on the world wide web.

Web site

Collection of Internet web pages belonging to a particular source.

Web TV

Internet services, including e-mail and online chats, that are displayed on the TV screen via a special web TV set-top box.


Web camera designed to upload digital images on to a web server, either via a PC connection or dedicated hardware.


Delivery of mostly non-interactive (i.e. linear) streamed video or audio content over the Internet using streaming media technology and analogous to broadcasts, delivering the stream to multiple recipients simultaneously.


Person(s) responsible for creating, maintaining and marketing a web site.

Weekly channel patronage

Measure of channels’ weekly reach, as recommended by the GGTAM guidelines, that employs a raised 5 consecutive minute threshold (basis of most reach estimates is a one minute interval), as the minimum duration of genuine viewing to a channel. Term is mainly intended for public broadcasting use.

Weight factor

Multiplication factor for converting the size of a sample to the population estimate for the survey universe.

Weighted average

Generally refers to the arithmetic average obtained by adding the products of numbers "weighted" by a predetermined value.

WFA (World Federation of Advertisers)

International trade association of advertisers.

Whole gap

Term used in data editing to denote an interval of uncovered viewing that lasts the entire viewing session.


General term for screen displays with a wider aspect ratio than the 4:3 aspect ratio employed by conventional TV broadcast channels. HDTV employs a 16:9 aspect ratio. Most feature films also employ widescreen aspect ratios, some times greater than 16:9.

Widget (Online)

Element of a graphic user interface (GUI) for arranging information (e.g. text box, window) that can be changed by the user.

Wi-Fi (Wireless fidelity)

Popular term for technologies based on the IEEE standards from the 802.11 working group on wireless local area networks (WLAN), though strictly defined as a certification mark of equipment conformity and interoperability, based on that family of standards. (see also WiMAX)

Wikimedia commons

Media repository that is created and maintained not by paid-for artists, but by volunteers. Its name "Wikimedia Commons" is derived from that of the umbrella project "Wikimedia" managing all Wikimedia projects and from the plural noun "commons" as its contents are shared by different language versions and different kinds of Wikimedia projects. Thus it provides a central repository for freely licensed photographs, diagrams, animations, music, spoken text, video clips, and media of all sorts that are useful for any Wikimedia project.


Worldwide Interoperability Access - Popular term for technologies based on the IEEE standards from the 802.16 working group (though like Wi-Fi strictly created as a certification mark of equipment conformity and interoperability based on those standards). Potential use includes enabling the delivery of wireless broadband access over the last mile as an alternative to wired delivery. WiMAX has much greater range than Wi-Fi and uses licensed spectrum. The two are widely viewed as complimentary technologies.

Windows media center

Windows application intended as a home entertainment hub. Designed to be viewed from distances up to 10 feet, its use can be extended to organising and relaying content for display on other screens in the home.


Although the old fashioned term for a radio transceiver, in modern usage wireless is a method of communication that uses low-powered radio waves to transmit data between devices. The term refers to communication without cables or cords, chiefly using radio frequency and infrared waves. Common uses include the various communications defined by the IrDA, the wireless networking of computers and cellular mobile phones.

Wireless broadband

Generic term for wireless technologies (including WiMAX or 3G mobile technologies) Internet solutions) that deliver high-speed Internet and data network access over wide areas in the order of several kilometres.

Wireless cable

Local distribution systems using broadcast technology (e.g. MMDS) for delivering extra channels locally to subscribers.

Wireless router

Wireless device for relaying incoming signals to selected destinations (e.g. routing incoming broadband signals to the TV set or PC).

Within programme break

Commercial break within a programme.

WLAN (Wireless LAN)

Wireless Local Area Network is any network linking two or more computers by means of radiocommunications technology and without the use of wire. The associated technologies and supporting standards enable communications within a specified area, offering significant advantages in terms of mobility, ease, flexibility and scalability of deployment.

WMA (Windows media audio)

Compressed audio file format developed by Microsoft, initially a competitor to the more popular MP3 format and more recently the Advanced Audio Coding now being used by the Apple iTunes media player.

WWW (World wide web)

Global telecommunications network giving access to the Internet.


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Free and open source MPEG-4 video codec. Xvid was created by a group of volunteer programmers after the OpenDivX source was closed in July 2001. Xvid is a primary competitor of DivX (Xvid being DivX spelled backwards). While DivX is closed source and may only run on Windows, Mac OS and Linux, Xvid is open source and can potentially run on any platform.


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Massively popular video sharing web site created in February 2005 and bought by Google Inc. in October 2006. In addition to film and TV video clips and music clips, the site is heavily used for vblogging.


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Flicking through different TV channels, often to avoid a commercial break.


Fast forwarding through recorded commercials when watching a home-recorded videotape.