TAM is an acronym for Television Audience Measurement.

TAM Ireland (Television Audience Measurement Ireland Ltd) was set up in 2007 to provide the industry-standard television audience measurement service for broadcasters and the advertising industry. TAM Ireland is owned by RTÉ, TG4, TV3, Channel 4, UTV, Sky, Viacom and Setanta. All of the major media buying agencies in Ireland are also members. TAM Ireland is a not-for-profit company limited by guarantee.

TAM Ireland commissions contractors to provide research services on its behalf, including the production of audience viewing figures. The audience measurement contract is currently held by Nielsen Television Audience Measurement (formerly AGB Nielsen Media Research). The contract for the Establishment Survey fieldwork is held by Behaviour and Attitudes.

Nielsen is responsible for providing estimates of the number of people watching television. This includes what channels and programmes are being watched and the type of people who are watching at any one time. Nielsen TAM provides television audience data on a minute-by-minute basis for channels received within the Republic of Ireland (ROI). The data is available for reporting nationally for terrestrial, satellite and cable reception for both analogue and digital platforms.

Viewing estimates are obtained from a panel of television owning households representing the viewing behaviour of the 1.5+ million TV households within Ireland. The reporting panel of 1,050 homes is selected to be representative of each region. The service covers viewing within private households only.

Panel homes are selected based on a stratified and un-clustered sample design so that the panel is representative of all television households across Ireland. A range of individual and household characteristics are deployed as panel controls to ensure that the panel remains representative. As estimates for the large majority of panel controls are not available from CSO data, it is necessary to conduct a bespoke survey (the Establishment Survey) to obtain this information.

The TAM Ireland Establishment Survey is carried out in three waves per year and involves approximately 6,000 interviews per year. It is a random-probability survey which means that every private residential household within Ireland has a chance of being selected for interview. The survey ensures that any changes taking place in the population can be identified so that the panel can be updated and adjusted to ensure that it continues to reflect the television-owning population. In addition to being the prime source of television population information, the TAM Ireland Establishment Survey also generates potential recruits from which panel member homes are selected.

When a household agrees to join the panel their television sets, PVRs, VCRs etc. are electronically monitored by a meter. Each TV in the home is connected to its own meter which holds an electronic record for the set. The meter is a small box which is put close to each television set and connected to it. The meter automatically identifies and collects information about the channel that the panel member is viewing.

All panel household residents and their guests register their presence when in a room with a television set on. Each individual does this by pressing a button allocated to them on the Unitam Meter handset. The metering system monitors all registrations made by each individual for each television in the home.

The panel member does not need to do anything else for the meter to capture the viewing in their household everyday. Throughout the day the meter system stores viewing undertaken by the entire household. Each night between 3am and 6am the data processing centre automatically downloads the data from panel homes (a process known as polling). This procedure is carried out on every panel home every day to produce minute-by-minute television viewing data.

Since September 2010 VCR, PVR playback and "catch-up" VOD services have been reported if it takes place within 7 days of the original broadcast. This viewing (known as time-shifted viewing) is added to the live data to produce the final, minute-by-minute Consolidated audience, available 8 days after the original transmission date. This Consolidated data is the 'TAM Gold Standard' used by the industry to report and trade on.

Channels reported by TAM Ireland provide detailed timings of the programmes and commercials they broadcast. The logs are then matched to the minute-by-minute viewing data to produce the TAM official audience estimates for programmes and commercials.

Live data reports viewing that takes place at the time of the original broadcast.

Consolidated data incorporates VCR, DVDR and PVR playback viewing that took place within 7 days of the original broadcast. This time-shifted viewing is added to the live data to produce consolidated viewing data. 

Consolidated data is available 8 days after the original transmission date. This data is the 'TAM Gold Standard' used by the industry to report and trade on.

Since September 2010, TAM Gold Standard data generally refers to Consolidated data which incorporates Live and Time-shift viewing. However, any audience measure that has been generated by applying the TAM-defined calculation methodology is TAM Gold Standard data. TAM Gold Standard data is used by the industry to report and trade on.

VOSDAL stands for Viewed-On-Same-Day-As-Live.

VOSDAL viewing includes time-shift viewing viewed on the same day as the original broadcast. It is included in the overnight files released at 9.30am the following day.

For example, if a film commences at 5.30pm and is recorded and then viewed later the same evening at 9.00pm, this viewing is captured and reported in the overnight file published the following day.

All individuals aged 4+ are measured and reported by TAM. Within this, a user may define and look at any age group they wish to report on

Viewing is reported by clock minute. Each clock minute is attributed to the channel that is viewed for the longest period within the clock minute, subject to there being at least 30 seconds of viewing and the viewing to the channel crosses the 30th second within the minute.

Programme audiences are calculated by averaging the audience of all minutes covered by the programme transmission, from the start-time of the programme until the end-time of the programme

The audience for a commercial is the audience for the clock minute in which the commercial starts

Since September 2010, non-live viewing from PVRs and other recording devices has been measured and included in the viewing figures as time-shift viewing.

When a programme has been viewed on the same day as the original broadcast the viewing is included in the overnight files as VOSDAL data. If it has been viewed within 7 days from the original broadcast, it is included and reported in Consolidated data

TAM viewing data is available for a range of audience data, including overnights, dayparts, programme and commercial information, reach and channel share of viewing. Data can be accessed as live, VOSDAL or consolidated data as of 01 September 2010.

Overnights are reported at a programme level for broadcasters providing logs on a daily basis and at a quarter hour level for all reported channels. This data is official.

The TAM reporting panel is 1,050 homes.

Panel homes are located across Ireland and represent the viewing of all individuals aged 4 and over within the household (plus their guests). These panel homes return data on a daily basis from approximately 1,800+ people. All terrestrial, analogue and digital platforms are included.

The maximum length a panel home is kept on the panel is 5 years.

Panel members are not paid for participating on the TAM panel. Instead they are thanked for taking part via a points system that allows them to redeem points for vouchers.

The TAM panel is designed to allow for continual change. Panel controls are deployed to ensure that the panel remains representative of the TV landscape in Ireland.

Quality control procedures are carried out on a continuous basis to ensure that the panel members are following the correct procedures. For example, telephone checks are often made to panel homes to verify that excessive viewing to one particular channel or nil viewing is genuine viewing behaviour.

The panel home will remain part of the daily reporting panel but obviously will not report any viewing.

An engineer will be sent to the panel home to connect the UNITAM meter to the new equipment to ensure that the viewing is captured and measured.

Whilst this is taking place, the panel home may be temporarily taken off the reporting panel until quality control checks are passed.

You cannot volunteer to join the panel.

Panel households are selected from Establishment Survey respondents with controls in place to ensure that all sectors of the population and all TV viewing environments in the home are represented

A panel member (or guest) is defined to be viewing when they are present in a room with a television set switched on

A universe is a population estimate for a particular audience category. TAM universes are based on television homes. For example, the universe for ABC1 Women is the total estimated population of ABC1 Women living within television households in Ireland

The TAM Establishment Survey is a survey undertaken to determine the ownership of television equipment and demographic characteristics of the population. It is a household-based survey covering over 6,000 interviews per year.

The results of the survey are used to determine the panel controls against which the panel is maintained. It is also used to provide universe figures for each demographic category required for reporting viewing data. The TAM Establishment Survey provides the pool of households from which TAM panel homes are recruited.

At present there are 33 channels individually reported by TAM. All other channels are reported under the group 'Other'. Total TV is also reported

Yes, every broadcast channel that can be viewed in the ROI is measured but only those channels that a broadcaster requests to be measured are reported individually. All other channels are grouped together with their viewing combined and reported as 'Other' which contributes towards 'Total TV' viewing

TAM does not measure viewing undertaken outside of residential households. However, visitors to panel households are asked to record their viewing. This is known as guest viewing. Guests are asked to provide details of their sex and age via the UNITAM meter handset. This provides an estimate of viewing that takes place outside the viewer's own home but within another private household

No. Radio listenership data is provided by the JNLR (Joint National Listenership Research)