Glossary

Average Hours per Head

The average length of time a person spends listening to a station. This is calculated by dividing the Weekly Hours by the Population.

Average Hours per Listener

The average length of time that listeners to a station spend with that station. This is calculated by dividing the Weekly Hours by the Weekly Reach

Efficiency Factor

The Efficiency Factor indicates the all-time efficiency of a station at delivering a given Target Market. This is calculated by dividing the All Adult Weekly Hours by the Target Market Weekly Hours.

Hours Index

The Average Hours for a station against a Target Market indexed against the All Adult Average Hours for that station. This indicates whether a Target Market is likely to listen to a given station for more or less time, with 100 being the norm.

Market Share

The percentage of all radio listening hours that a station accounts for within its transmission area. This can be calculated for any target market across any area.

OTH

Opportunity to hear.

Population

The number of people aged 15+ who live within the TSA of a given station.

Reach Index

The Weekly Reach % of a station against a Target Market indexed against the All Adult Weekly Reach % for that station. This indicates whether a Target Market is more or less likely to listen to a given station, with 100 being the norm.

Share Index

The Market Share % of a station against a Target Market indexed against the All Adult Weekly Reach % for that station. This indicates whether a Target Market is more or less likely to listen to a given station for more or less time, with 100 being the norm.

Share in TSA

The percentage of total listening time accounted for by a station in its Total Survey Area in an average week. This is obtained by dividing the station’s total hours by the All Radio total hours in the station’s TSA.

Survey Period

Depending on the size of their Total Survey Area, stations report on a sample based on 3, 6 or 12 months. This is the survey period and is denoted by the letters Q (Quarter), H (half yearly), and Y (yearly).

Total Survey Area

The area within which a station’s audience is measured. This is defined by the station using postcode districts as building blocks.

Total Weekly Hours

The total number of hours that a station is listened to over the course of a week. This is the sum of all quarter-hours for all listeners.

Weekly Reach

The number of people aged 15+ who tune to a radio station within at least 1 quarter-hour period over the course of a week. Respondents are instructed to fill in a quarter-hour only if they have listened to the station for at least 5 minutes within that quarter-hour. Between 24.00-06.00, listening is recorded in half-hour periods.

Weekly Reach %

The Weekly Reach expressed as a percentage of the Population within the TSA.