As part of an effort to harmonize its national audience data and the way clients and third-party processors utilize it, Nielsen Media Research will issue a "new set of calculation rules" during a
meeting of TV ratings data processors in Arizona later this week. The plan, which was first unveiled during Nielsen's national client meeting in Florida last month, is part of an effort to move its
entire national database system to a single, "respondent-level source," as well as a single application.
