TV Audience Measurement

Every year, Finnpanel conducts an establishment survey where we study TV device configurations, signal reception and known channel penetration in Finnish households.

Since 1995, the establishment survey has been conducted as a postal questionnaire. The survey is conducted four times a year using a random sample of 3000 households from the people registry.

One of the functions of the establishment survey is to provide a sample source for the TAM survey. It must have a sample good enough to provide public statistics as well as control data for the TAM survey. The establishment survey is used to study the population regarding factors that are essential to TV viewing. These factors are for example ownership of VCR, remote control, satellite dish, digtal set-top-box and number of TV sets in the household, cable TV coverage, and channel (pay and non-pay) selection.

The sample of the TAM survey consists of 1100 households totaling approximately 2300 respondents older than 4 years. These respondents are weighted to present the 4+ population in Finland. One respondent represents approximately 2200 other people of same age, sex and living location. This factor is approximately 3400 in Sweden, 6100 in Germany, 4600 in Great Britain, 6300 in France and 4100 in Spain. ´

The representativeness of the panel is monitored constantly. Finnpanel regularly produces a so called sample report where the structure of the sample is compared to the demographic information and other statistics. This is an important issue that affects the reliability of a panel survey; the panel sample can be fixed if it becomes distorted (for example, contains too many cable TV households. Ad hoc surveys do not have this benefit.

Because the TAM survey is based on a random sample, not everyone can join the panel. The establishment survey questionnaire is mailed for times a year to 3000 people randomly selected from the People Registry. In that questionnaire, the respondents are asked if they are interested in joining the panel. If they are willing, their data in included in the database where we select new households as needed.

The Finns wach TV a bit over two and a half hours each day. One third of the panel members watch TV over three hours a day and one third spend less than one hour a day watching TV. On averge day, approximately 20 % of the panel members do not watch television at all. This means that both heavy and very selective TV consumers are presented in the panel. The amount of viewing correlates with age — older people spend more time watching TV than the young.

All personal information of the panel members is confidential. Each panel member has her/his own ID number and the vewing statements are analyzed using these IDs. Personal information is known only to those people in Finnpanel that need it in their work. This information is never released to anybody.

When a meter is installed to the household, Finnpanel's technician provides guidance for using the meter and gives the household a user manual for the meter. After this, the household has a learning period of few weeks. When using the meter has become routine, the household is included in the panel. This minimizes the so called panel effect (=being included in the study affects the study results).

In analog TV sets, the meter works as a tuner. The installation is easy because opening the TV set is not required. The meter has a clock, battery for power failures and a modem that is used to transfer the data. There is also a remote handset that panelists use to declare their presence when wathing TV. All the TV sets in the household are connected to the metering hardware.

The viewing data is stored in the meter. The data from all meters is downloaded to Finnpanel during the night (between 2:00 and 5:00 o'clock) using a modem.

When the TV set is switched on, the meter display prompts "Who Is Watching?". Household members that are present declare themselves by pressing an individual presence button in the remote handset. A presence indicator for each person is shown on the meter display. When they leave the room they press the button again and the presence indicator clears. Each houshold member has her/his own button on the remote. The guests of the houshold also declare their presence using the remote when watching TV.

Pressing the presence button is all that needs to be done. The channel and time is identified by the meter and this data is then matched to the program.

The panel members are instructed to use their presence button whenever they are present in the room and able to watch TV.

Households with harddisc set-top-box are equipped with meters which identifies the program based on audiomatching.

The households receive an incentive of 168 € each year. This income is subject to taxes.

The yearly panel turnover rate is 25 %. In practice, this means that 20–25 households are replaced each month. It is important that the panel structure follows changes in the society and TV issues. For example, the number of one-person households has increased during recent years and respectively the number of larger housholds has decreased. The number of households that have several TV sets has been increasing for several years and therefore the change has also occured in the panel.

The measurement is accurate to the second and includes data about the channel and which members of the household are watching. The meter clock is synchronized each day during data collection.

Continuous viewing of a channel for at least 10 secods is registered. The second by second data is consolidated to minute data. The channel that was watched during the last second of the minute is credited to the whole minute. The viewer estimate for the minute is calulated by summing all viewers in that minute.

The transmission logs from the TV stations are transferred to Finnpanel during the night. The logs contain names for all programs and spots and the exact start and end times. This data is matched by time to the viewing data from the meters.

The panel households are required an over-all commitment to the survey, confirmed by a signed agreement. All panel households are guided personaly in their own homes during the meter installation. Participation to the survey does not mean that viewing habits should be changed in any way. New housholds first face a learning period during which they practice using their presence buttons and form a routine habbit of it.

They also receive a user manual for the meter. Despite all this, it is clear that sometimes they forget to press their presence buttons. In order to minimize the errors, the meter constantly displays the ID letters of all members (and guests) that have declared their presence.

Finnpanel regularly contacts the panel housholds and remind them of the importance of using the presence buttons.

The system has built-in checks that can discard faulty data. Among this checks are:

1. Events where the TV set had been switched on without any viewers declared are automatically discarded. Amount of these events is approximately 5 % of all data.

2. Events for unknown household members are discarded.

3. One person can watch only one TV set at a time. If a person declares herself/himself to several sets, only that latest declaration is acknowledged.

4. Panel members that have extensively long viewing statements or do not watch at all during a certain period are listed and the reason for the anomaly is investigated.

If these anomalies are received continuously from the same household the household is contacted to find out the reason. It can be a techical failure in the meter but sometimes it is due to ignorance by a panel member. If the ignorance continues, the household is removed from the panel.

A study investigating the usage of the presence buttons (validation study) is conducted yearly. The study is conducted as a coincidental interview where the household is contacted by phone and asked which members of the household are currently in the rooms where the TV sets are located. The results are compared to the data from the meters, thus finding out the errors in presence button use.

According to the latest validation study, the net effect of incorrectly declared viewers to the measurement results is very small.

There are two main methods for reporting TV viewing

1. An overnight is produced each day. The report contains ratings for previous day's programs of all major TV channels. The demographic group of the report is 10+ years old population including guest viewing. The ratings and shares are calculated for each program and 15 minute period.

2. There are software tools to analyze the data to produce ranking lists, campaign analysis, frequency analysis etc.

The fllowing figures are calculated:

Estimate

Number of viewers (in thousands).

Cover %

Number viewers proportional to the population of the target group.

Profile %

Proportion of the target group's viewing of the programs total audience.

Share %

Channel's share of total TV viewing.

Reached Audience

Reached audience of 10+ population, either in thousands or per cents.

Average Viewing Time

Time (per person) spent viewing the channel during a day

The rating for the program is the average of minute ratings during the program.

Example: Program (10 min)

Minutes
 1        220 000         
 2        220 000         
 3        225 000         
 4        240 000         
 5        250 000         
 6        250 000         
 7        255 000         
 8        270 000         
 9        280 000         
10        280 000         
Sum     2 490 000

Rating for the program: 2 490 000 / 10 = 249 000

As in all surveys based on sample the figures reported are not quite exact. The size of the sample has a direct effect on the margin of error. In the tv audience measurement  the margin of error is approx +- 2 % units. So if the audience of a program is 300 000 , the margin of error is about +- 50 000.