• by Dana Blankenhorn , March 19, 2003

Starting Monday Arbitron ratings for national radio commercials will be compiled entirely through diaries.

Arbitron has been moving its RADAR (Radio’s All Dimension Audience Research) service from a telephone-interview to a diary base for the last four years, said spokesman Thom Mocarsky. With RADAR 76 the transition is now complete.

What does that mean for the ad buyer? "Finer detail and more stable demographics," Mocarsky said. With 50,000 diaries replacing 12,000 phone calls, smaller networks will also have reliable audience measurements.

"They get finer detail in their demos, more stable estimates, more stations aggregated into the networks. Plus we can do weighting improvements, for more reliability," Mocarsky added.

Arbitron has been working on this transition since it acquired RADAR from SRI. The methodology has won approval from the NRRC (Network Radio Research Council), which reviewed a test showing that diaries produced a balanced sample consistent with population projections.

Diaries are balanced among 16 discrete sex/age groups; four census region groups; five county size groups and three household size groups; as well as race and ethnicity.

Buyers can use RADAR numbers to show that, say, commercials on ABC FM Connection garnered a specific nationwide rating for a specific demographic. "We’re not specifically saying this one commercial did this," Mocarsky cautioned. "But if the station didn’t clear, it doesn’t get reported as a rating for the network.

"There’s an additional component to RADAR that’s important. We match the audience to the commercials, and run verification on whether the commercials actually ran. For the advertisers this is critical." Commercial verification methodology has been built into RADAR from the beginning.

With large national networks now dominating the radio business, RADAR has becoming increasingly important. But this doesn’t replace Arbitron’s LMRS (Local Market Radio Service), which compiles ratings in 286 markets and has always been done on diaries.

"In terms of raw technologies diaries are more current than telephone," Mocarsky added. "Telephone was introduced to radio ratings in 1929 by Crosley. Household diaries were introduced in 1949 for television, and then in 1965 to radio" for local ratings.

"RADAR did a good telephone interview. They recruited you in advance and called you every day for a week. But even then you were doing a lot of recall. The diary is just an easier tool to use. Most tend to be filled out as we go along. When someone makes a commitment they’re usually pretty good at it."

Best of all, ratings are now being compiled using the same method across all electronic media. "The strengths and weaknesses of any methodology are now common in national and local radio."