How we do what we do

Have you ever wondered how BARB measures television viewing for the whole of the UK?

These three videos explain how we do what we do, including how the BARB panel works and how we retrieve our data. There is also information below if you would like to read further details.

Since 1981, we at the Broadcasters’ Audience Research Board (BARB) have been delivering the official viewing figures for UK television audiences. We commission research companies Ipsos MORI, Kantar Media and RSMB to collect data that represent the viewing behaviour of the UK’s 26 million TV households.

BARB viewing data offer clients, such as broadcasters and advertisers, a minute by minute breakdown of viewing at regional and national levels. This information is vital for assessing how programmes, channels or advertising campaigns have performed and provides the basis for airtime advertising trading.

In order to estimate viewing patterns across all TV households, a carefully selected panel of private homes is recruited. The Establishment Survey is carried out continuously by Ipsos MORI in order to track changes in UK household characteristics. From this we can ascertain the types of households we need on our panel to make sure it is representative of the whole of the UK. We then recruit households to be on the panel that suit the necessary demographics, TV platforms and geography, as well as other variables. The BARB panel consists of 5100 households, which each represent about 5000 other households across the UK.

Once a household has been recruited to the BARB panel, Kantar Media fits every TV set in the home with a meter. Software meters are also installed on laptop and desktop computers, and tablets. In order for the meter to know who is watching, each member of the household over the age of four is assigned a button on a special remote control. If they enter a room while the television is on they must press their designated button to register their presence and press it again when they leave to show they are no longer watching.

We know what panel members are watching through an audio matching process. The meters take an audio sample of the programme, which is then turned into a digital fingerprint and matched to a reference library of programmes. It takes 15 seconds for the audio to be recognised and therefore matched but we report viewing on a minute-by-minute basis.

When two channels are playing the same content, for example one in standard and one in high definition, the broadcaster applies an audio watermark. This is inaudible to the human ear but can be picked up by the meter, allowing it to allocate the data correctly.

We have an additional technique for homes that use Sky, which involves accessing service information codes from the set-top box. We have also started working with metadata tags, which are embedded by broadcasters into online television content.

The data from the panel are sent back to Kantar Media at 2am before being processed and weighted to be representative of the whole of the UK. They are then released to the industry at 9.30am each day. These figures are called ‘overnights’ and show all of the previous day’s TV viewing.

These figures not only include those who watched the programme at the time it was broadcast but also those who recorded it and watched it back the same day. This is referred to as ‘viewing on the same day as live’ or VOSDAL.

Overnights however are not the viewing figures that appear on our website. These are consolidated ratings and include catch-up, or time-shifted, viewing that happened up to seven days after the original broadcast. The consolidated ratings are the BARB gold standard on which the UK broadcasting and advertising industries rely for all reporting and trading.

We are also now able to measure time-shifted viewing that happened up to 28 days later. All of our data is matched to the programme and advertising schedule to give viewing estimates for every programme and commercial that has been broadcast.

We are continuously monitoring changes in the UK’s TV viewing behaviour and developing new ways in which we can measure this. For more information on BARB’s plans for the future please click here.