Lots of today’s RAJAR press coverage focuses on the “battle” between Radio 1’s Chris Moyles (34) and Radio 2’s Terry Wogan (69). There are charts like the one below, a version of which appeared in today’s Times.

It all looks pretty close between the two breakfast DJs.
But is that chart completely fair? Chris Moyles is seemingly getting very close to catching Wogan. I’m sure it’s a great story for BBC PR to be talking about. But it’s not really comparing like with like.
The numbers being talked about are weekly “reach” figures – the number of different people, in the course of a week, who listen for at least 5 minutes to a particular show. But while Terry Wogan’s show runs for two hours daily from 7.30 – 9.30am, Chris Moyles’ show runs for three and a half hours from 6.30 – 10.00am. If you have a longer show, you have more opportunity to generate a higher reach figure.
It’s an old radio trick to bump up listening figures by extending a show since ordinarily journalists and others will just compare the overall figures with one another without regard to a show’s a length. Indeed, if you’re being really unscupulous, you might compare your new longer show’s figures with your previous shorter show’s numbers. Unless you’re doing something really wrong, you should see a nice increase!
But occassionally it does cause difficulties. If you look at the reporting of the London breakfast show marketplace, you’ll see that Capital 95.8 is crowing because Johnny & Denise is the biggest commercial breakfast show with 943,000 listeners. But Johnny & Denise run from 6.00 – 10.00am, whereas Jamie Theakston & Harriet Scott on Heart only run 6.00 – 9.00am. If you compare the audiences for those shorter hours, then Jamie & Harriet get 893,000 listeners, while Neil Fox over on Magic gets 831,000 (his show ordinarily runs 5.30 – 9.00am), and Johnny & Denise get “just” 829,000 listeners. That 9.00 – 10.00am hour is pretty big, and if your DJs are willing to work it, then you get quite a bump in your overall figures.
Depending on how you cut the cake, you get different results.
So what would the chart look like if we compare like with like hours for Wogan and Moyles, using Wogan’s more restricted 7.30 – 9.30am hours? Something like this:

OK – it’s a little hard to see without rescaling the charts a bit (something I currently can’t do with Google Spreadsheets), but instead of a difference of 380,000 between the two in the most recent results, the “fair” difference is actually 1.02 million which is still quite considerable.
So always be a little aware about what’s being compared and between who.
As ever when talking about radio, these are my own opinions and do not represent those of my employer.