Gues We Were All Wrong

[rogerkirk]

Garrett Wollman wrote:
>Well, it really depends on how you define "accurate".  The diary
>system and the PPM measure different things: the diary measures
>*recall* and the PPM measures *audience*, without any knowledge of
>whether the participant is actually paying any attention.  I don't
>know if either one correlates well to advertising response rate.

It would be instructive if a PPM wearer also kept a diary.  And the the two results were correlated.