Whats this Channel4 ?

TV Ratings

Ratings are very important to all broadcasters, but to a commercial service like Channel 4 they are critical. A very large proportion of the Channel's revenue (around 85%) comes from advertising. If it cannot show that it has enough viewers, or enough of the kind of viewers that advertisers want to target, then advertising revenue will fall. If advertising revenue falls, then the Channel, like any other business, must either cut overheads or spend less money on making programmes. So like all broadcasters, Channel 4 is very alert to ratings, and it gets information about who is watching from BARB (Broadcasters' Audience Research Board).

BARB is the main source of television audience data in the UK. BARB was set up in 1981 to provide audience measurement for television broadcasters and the advertising industry. BARB is a limited company owned by the BBC, ITV, Channel 4, Five, BSkyB and the Institute of Practitioners in Advertising.

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Television measurement service

The measurement service provides minute-by-minute television audience data on the channels being watched in the UK.

Viewing estimates are obtained from a panel of 5,100 television owning households. The panels are selected to be representative of each ITV and BBC region as well as being representative of the whole population.

Each panel household has all its television equipment: sets, video cassette recorders, set-top box decoders etc, electronically monitored by a 'people-meter.' This system identifies and records to which channel each television set is tuned and any programme that is 'time-shifted' on a video recorder.

To make sure that the panel is fully representative of the 24 plus million households within the UK, BARB conducts a large-scale survey called the Establishment Survey.

The Establishment Survey is a random survey carried out continuously, involving some 52,000 interviews per year. The survey ensures that any changes within the viewing population can be identified and the panel sample can be adjusted accordingly. For example, recent changes have increased the representation of downmarket households generally and all households in London.

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What is measured?

Audience categories

The main audience categories are: individuals, adults, men, women, children, and housewives. These are further subdivided by age and social class.

Audience sub-categories/sub-demographic groups

The division of the main audience categories is by age and social class. Social class is determined at the household, rather than the individual, level. The classes are:

AB - higher (A) and middle (B) management, administrative or professional
C1 - supervisory, clerical, and junior management
C2 - skilled manual workers
DE - semi-skilled and unskilled workers and non-wage earners.

AB and C1 audiences are sometimes described as 'upmarket', C2, D and E are correspondingly described as 'downmarket'.

Age divisions generally used are:

4-9 years; 10-15; 16-24; 25-34; 35-44; 45-54; 55-64 and 65+ (although 55-64 and 65+ tend to be replaced by 55+).

Broadcasters may be neutral about which sub-category watches their programmes but advertisers are not and tend to prefer younger and more upmarket audiences. Both groups watch less television than the population generally, so getting to them appeals to advertisers. Beyond that, upmarket audiences have more to spend, and the 16-24 age group has no clearly established patterns of consumer spending, another appealing factor for advertisers.

Audience share

'Share of viewing,' 'percentage share' or just 'share' are different ways of expressing the percentage of the total audience that is watching a particular channel. Channel 4 typically manages a 10% share.

Flow

Audience flow is an analysis which shows how many viewers, at each minute, are watching the same channel as in the previous minute. Flow is used by broadcasters to construct competitive schedules.

Index

This is a measure of the size of a sub-category of the audience. For example, if the index for 16-34 year olds is 100 it means that the audience for that period contains the same proportion of 16-34 year olds as are found in the general population. If the index is 120, then 20% more 16-34 year olds are watching than in the population at large.

Loyalty

The percentage of the audience that is watching at the beginning that is still watching at the end of a programme.

Reach

The percentage of the population who see a specified amount of a channel's output, over a specified period. Channel 4's weekly reach is 70%, which means that C4 reaches 70% of all viewers weekly.

Share of viewing

The percentage of time that each channel is viewed by a target audience. On average, adults view Channel 4 for 11% of their viewing time.

Target audience

This is a measurable (BARB) definition of those people a channel wants to reach. The universe is the total number of people in that target audience.

TVR (Television Rating)

TVR is the percentage of the total number of those that could view a channel, who are viewing. For example, if a soap opera achieves a '16-34 TVR of 30 in Scotland', this means that 30% of all 16-34 year olds in Scotland watched at least one average minute of that episode.

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