Arbitron says data from its Portable People Meter Data are reliable — this after some reports this week that in-tab numbers from Houston had dropped.
At a meeting in Columbia, Md., for programming consultants Thursday, Bob Patchen, chief research officer, said there was a “glitch” in the report, not a sample size change.
“This is obviously a bad time for us to make a mistake,” said Patchen. “It should have been caught in quality control process and it wasn’t. That process is being reviewed, and we’ll go forward.”
Arbitron puts the average daily sample size for the month of July at 1,168, which is 193 below its target.
Several factors have led to a sample delivery under target, Patchen said. In the diary, people cooperate for a week. With PPM, people participate for a year or more. Some people cooperate less over time, and Arbitron says it now realizes it needs to move faster to remove poor responders from its panel. Summer vacations have affected this situation also, he said.
The company hopes to be up to its full average daily size target in Philadelphia in September and early October in Houston.
Arbitron CEO Steve Morris said managing large panels of people carrying meters for such a long time is “unprecedented” for the company, however he said the glitch hasn’t affected the validity of the data. “If it did, we wouldn’t send it out.”