Wednesday, August 05, 2009

Following The Bouncing PPM Data

Todd Wallace, DJ/PD/Programming Consultant/Researcher/Publisher known as the 'Father of Callout Research', which he pioneered in early 1970s writes to correct my semantics. In yesterday's post, I termed fluctuations in PPM weeklies "wobbles." Todd points out that a better word for it may be "bounce."
While the target sample-size in meters for most major markets is larger than the average number of monthly diaries were, it is much smaller than the quarterly total of diaries and unique households sampled over the 84 days of the quarterly survey in a typical Arbitron diary “book.”

What this means: while there will be less sampling “wobble” than we would have seen with diary monthly-isolations, there may be more such “bounce” when compared to a full quarterly diary report.

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