It's been some time since we had a new problem to cite for the Nielsen conspiracy theorists. This one isn't likely to fill their tanks, but it'll keep them going for awhile.
The in-panel study is somewhat controversial, in that it contacts people who are active participants in Nielsen's TV ratings panel to find out if they are pushing their buttons correctly, something some researchers feel could influence their behavior, and the outcome of the ratings research. But Nielsen said it is fielding these studies periodically with the full knowledge and cooperation of its clients and "industry groups."
Like past studies, the April research indicates relatively high "agreement rates" between Nielsen's people meter ratings panels and the behavior reported in the validation studies, which contact people by phone and ask them what they are watching on TV. The April study, the fourth conducted so far, yielded an overall agreement rate of 90.31% vs. an average of 88.97% for all four waves.
via MediaPost .