Outside of the UK, the predominant radio measurement methodologies are a similar diary-based system, a day-after-recall approach or a form of electronic measurement.
This could be referred to as the “what did you listen to yesterday/in the last few days?” approach. The participant or panel member is contacted by telephone, online or even in person and asked to recollect what they listened to previously. This method can be used as a sole form of measurement or as part of a hybrid system.
Electronic Measurement (EM)
Electronic measurement is used as the main audience measurement system in the major US markets, Scandinavia and some other European Countries. EM has also been introduced in a small number of other countries in parallel with the legacy methodology as a hybrid or fusion method. Electronic Measurement has two forms;
- Encoding - a watermarked signal/inaudible code is inserted into the broadcast audio, which the human ear cannot discern but the receiver device picks up and registers as listening or exposure.
- Audio Matching – a computer stores timed samples from available audio/radio services several times a minute. The data is then matched to audio samples captured by a device (e.g. a watch or phone) carried by a selection of panellists. Any matches above a set level of probability are deemed to be evidence of listening or exposure.
Since the conception of RAJAR, it has vigorously tested many forms of electronic measurement. Five years ago, RAJAR completed a major review of the viability (technical and economic) of a variety of electronic measurement techniques, which included the world’s first multiple-meter trial, and concluded that the unique nature of the UK radio landscape did not lend itself to the then-available EM solutions for two main reasons. Firstly, we identified a compliance issue, notably around peak-time, and secondly, in the UK there is a requirement to measure the specific platform (AM/FM, DAB, etc), which some EM devices were unable to do.
In addition, the cost of EM is high, complicated by the UK’s unique market structure of 300 stations and over 500 geographic segments that need measuring.