Nielsen's set-top test pattern: study with charter finds box data can improve local ratings.(PLATFORMS)

Data culled from cable and satellite set-top boxes has been used for years by various research firms and operators to report on and analyze TV viewing--but Nielsen has remained cautious about using those metrics as part of its ratings calculation.

Now, Nielsen has evidence that set-top data can markedly improve the accuracy of its local-TV ratings. Earlier this month, the New York-based information and research company shared results from a test last summer in three markets in which it used set-top box data from Charter Communications to refine ratings at the local level.

A key finding: By interpolating set-top data, Nielsen was able to eliminate between 50% and 90% …