Downloads:

New Nielsen Data Streams Show Strange Anomalies

Now that Nielsen has begun adding DVR data into its ratings, a strange occurrence has caused confusion among clients: some ratings and demographics are actually declining when the DVR data is added back into live ratings, Mediapost writes. Two explanations have surfaced.

Nielsen has reminded clients that the live ratings have included estimates for VCR audiences for about 20 years. The math created by Nielsen to calculate VCR audiences was designed only for its live ratings stream. When applied to the samples in its new DVR data streams, the VCR math changes the numerator and denominator, yielding “aberrations,” the company has said. Nielsen is still trying to understand all the ramifications of the new data streams, but any aberrations should diminish as the DVR sample grows.

But some believe that the anomalies may be caused by the weighting system Nielsen uses to adjust its ratings based on the composition of certain demographic groups in its samples. Nielsen’s calculation systems are so complex, particularly since they’ve weighted people in the database “so that a person is not simply a person,” said Tim Brooks, vp research, Lifetime Television. “Therefore, when they do multiple calculations, they run the risk that people who were heavily weighted in the ‘live’ sample may not be in the playback sample,” he told Mediapost.

Nielsen’s addition of DVR playback viewing to its data streams has been controversial. Media buyers want live viewing data, because advertisers are unsure of how much of the DVR playback might be fast-forwarding through commercials. But TV sales executives want to base deals on seven days’ worth of DVR playback viewing.

In November, the six major networks held a press conference to urge advertisers to consider DVR playback viewing when making their media buys. Other than disaster-relief benefits, this was believed to be the first time the networks had made a joint presentation on advertising-related issues, proving just how important the topic of DVR playback viewing has become.