Thursday, July 30, 2009


I avoid covering current events. I stand by that generalization. I always say that when I feel the need to cover them but of my average 250 some posts per year about two are about current events. Onward to the math...For months now we've all been reading about civic organizations, state attorney generals and radio stations suing Arbitron over PPM. I've written before about the natural predisposition of radio to reject all new numbers, especially any numbers that imply your listenership is down. But the reaction to PPM was way over the top.. I was even beginning to suspect that there was some validity to this just because of the wide-spread hostility. Then the story came out today. First thing today the Taylor on Radio-Info newsletter was in my inbox.
“Hispanic stations lost an average of 42% of their AQH ratings with 18-49s, urban stations an average of 34%…” That’s in the latest analysis across all 20 PPM markets done by consultant Randy Kabrich of Arbitron’s previous-diary-book ratings (not shares, but AQH ratings), compared to the latest June People Meter numbers. Kabrich says by comparison, “the non-ethnic-formatted stations lost an average of 16% of their ratings but held their ranks.” While the more serious loss of AQH ratings by the Hispanic and black stations had notable consequences for their ranks. Hispanic stations dropped an average of five ranks, compared to the diary. Urban stations dropped two ranks. Kabrich’s conclusion – “from diary to PPM, in currency ratings, the urban and Hispanic stations have more than double the loss of the non-ethnic stations.”
That just cant be right. First assumption. In the last 3 months 44% of Hispanic radio listeners didn't change the channel. Therefore the number was either too high before or too low. Around 4:30 FMQB sent out their email chiming in on the same topic with similar aplomb. they too were focused on Randy Kabrich, but hits a different more revealing quote:
"Share, which Arbitron uses, is not only not currency, it really can't be used to compare diary to PPM because of the vast differences in the PUR [Persons Using Radio]." Kabrich added, "Arbitron continues to use 12+ share in their comparisons which not only disguises a number of these issues, it is simply not currency and is irrelevant."
Randy is calling out Arbitron on the misuse of sample size. Sample size matters. But, here's why I think Randy is full of crap. Arbitron is guilty of using undersized samples. But, even previous to this the data was blatantly, criminally, unreliably, flawed! It was a diary system loaded with omission, falsehood, bias, non-response, error, and still yet some pretty small samples. If your data sucks it does not matter how big the sample is. It's just wrong. A bigger serving of crap is still crap. 60% more crap? Yes, still crap.

The PPM system removes every kind of error except the under-sized samples. If they samples are heinously undersized what we'll see is a wide variance between books. I don't see that. I think the shift is largely a correction. But not solely.

4 weeks ago Randy made a play for the same story but was focused on Urban radio. Story here. Edison makes the same assessment that I did: undersized samples vary, bias samples skew. Edison research makes the appropriate assessment of Randy's report:
"I simply couldn't understand what Randy was seeing. In the case of KMJQ (the blue line), one sees consistent upwards movement, while the PPM sample goes both up and down. KBXX (the red line) sort of stumbles along until their numbers shot up dramatically, again while the PPM sample gyrates around...We also ran an Analysis of Variance test (ANOVA) and found that the sample size is not associated with the AQH for either station."