Glossary of Radio Terms
Average Weekly Hours per Listener
The total hours of listening to a station averaged across the total relevant population. This is calculated by dividing the Weekly Hours by the total population for the audience concerned.
Cost Efficiency Factor (CEF)
Cost of reaching one thousand people in a target audience i.e. the cost of reaching a thousand listeners with a given advertisement. Cost per thousand is a means of comparing the efficiency and value offered by different stations.
Day parts are used to describe different times of day that you can target your ad campaign within. The two major day parts on radio are ‘Breakfast’ (typically 6-9am) and ‘Drive’ (typically 4-7pm).
The number of times a campaign is heard by listeners expressed over a period of time.
Gross Rating Points (GRPs)
GRPs are the Gross OTH of a campaign expressed as a percentage of the target market. One rating point equals one percent of the population. If a schedule attained a gross OTH of 200,000 for a target market of 50,000 individuals, it would generate 400 GRPs. Calculated by multiplying OTH by Weekly Reach %.
Impacts are the gross number of opportunities to hear (OTH) an ad. In terms of radio research, one impact is one person’s listening to one spot. These are added together to give total impacts for an advertising campaign, or total impacts for all commercial airtime on a certain station. Calculated by multiplying OTH by Weekly Reach (‘000s).
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 stands for Opportunity to Hear and represents how many times a listener is likely to hear an ad.
The number of people who live within the TSA of any given station.
RAJAR (Radio Joint Audience Research) was set up in 1992 to design and operate a single audience measurement system for the UK radio industry serving both BBC and commercial radio stations.
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.
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.
Total Survey Area (TSA)
TSAs are the area within which a station’s audience is measured. This is known as the station’s total survey area or transmission area.
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 represents the number of people who tune in to a radio station within at least 1 quarter-hour period during a week.
Weekly Reach %
The Weekly Reach expressed as a percentage of the Population within the TSA.