• by Joe Mandese  @mp_joemandese, December 10, 2010

Nielsen Thursday notified clients that it will restate ratings for nine TV stations in four of its metered markets due to a problem with the "software logic" used to process its ratings data. Nielsen said it has identified the problem, and is in the process of implementing a solution that will ensure it will not impact audience estimates for November, a crucial period for local TV advertising sales.

Nielsen said the nine stations affected were in Albuquerque, Austin, Birmingham and Indianapolis, and that they all fit into a category known as "parent + satellite stations," meaning that they were local stations (satellites) that rebroadcast the signal of another local (parent) station, a technique used to broaden the stations' combined geographic reach. Nielsen's policy is to report the combined audiences of those stations as a single entity.

Nielsen did not explain what caused the faulty ratings processing software, but said it detected the problem while comparing its metered ratings data with diary data in for those stations, and said that it found that demographic estimates for those stations were "misreported."

"The 'overnight' household ratings for these stations and all reported ratings for all other stations in these markets were not impacted," Nielsen said.