Measuring the effect of radio is the same as for any medium, except that radio involves one additional factor to take into account - media misattribution.

In awareness research surveys consumers tend to misattribute radio advertising memories to other media, particularly TV. This is most likely to happen when there is a strong execution link between the two media, and/or where there is an established history of TV advertising for the brand.

This understatement of radio can persist even when consumers are specifically prompted in surveys to think solely about advertising memories from the radio (see "Accessing Radio Memories" at RAB OnLine).

The misattribution effect brings good news and bad. The good news is that TV advertising awareness levels can be kept up by using radio - usually at a fraction of the cost (this is sometimes called "Virtual TV")!

The bad news is that it does not allow the marketer to measure how efficiently his/her radio advertising is working.

A pragmatic solution to misattribution: split research samples

The research sample should be split into two matched sub-samples. One should be Listeners (target consumers who have been listening to the stations which carried the ad campaign) and Non-Listeners (people who do not listen to those stations but who are the same as the listeners in all other respects, especially consumption of other media).

For more information on issues in this area, see the RAB guide to measuring radio’s effect.