Rajar contacted me to clarify the unaccounted for 21% of radio share. Rajar goes to great length to explain to its interviewees how to fill in their diaries, but in spite of this 21% of respondents are unable to confirm what platform they are using when listening to radio. Sometimes this may be attributed to unfamiliar locations, for example listening at a friend's house. But most of the time it is genuine uncertainty about what technology is being used. Rajar suggests that it is a positive achievement to identify nearly 80%, and indeed they should be commended for introducing this valuable research. We will examine the next quarter's results with interest for first signs of trends between platforms. But the fact that more than a fifth of listening hours are unidentified, even after extensive research and interviewee coaching, demonstrates how fragmented and complex the radio industry has become in the space of only a few years. Programme producers and broadcasters will be concerned to obtain even better clarity in order that investment decisions can be justified.