New research by the American Association of Advertising Agencies (AAAA) and the Association of National Advertisers (ANA) - which describe it as a first step toward increased marketing accountability - has concluded that, on average, some 5 percent of the reported program audience is lost when national commercial positions are run. Depending on program type, however, that percentage can vary widely, according to an announcement released yesterday.

The overall intent of the organizations is to examine the measurement of TV audiences to improve accuracy. The AAAA/ANA conducted the initial study to understand the dynamics between TV program ratings and commercial ratings.

The joint AAAA/ANA task force that oversaw the study notes that technologically advanced television-viewing behavior can limit accurate measurement. The analysis did not include local commercial audiences or DVR/VCR usage; also, channel switching is captured by Nielsen Media Research only if the behavior is substantive enough - rapid channel switching is likely not captured. As a result, accurate measurement is limited.

Nielsen provided two months of program and audience data for broadcast, cable, and syndication, and the information was independently analyzed for variances between program and commercial audiences. The study focused on commercial ratings in :30 increments - and compared them with their corresponding program ratings.