Arbitron - The Diary
The Arbitron Diary
 This is the cover of a sample diary (samples have a nice little hole in them) which participants in the survey receive, along with a cash incentive.
How to fill in a Diary
Participants get precise instructions on how to fill in their diary. They are told to show the time, name of station or other identifier, and location of listening for each day of the week.

The diary is still used in markets 51-300 by Arbitron, since the methodology is accredited and vastly less expensive in markets with lower revenue bases.
Further information is available at www.arbitron.com.
(Sample Arbitron home page - click for larger version)
 
Instruction page for a diary.
Bilingual diaries are sent where they are likely to be needed.
One of the seven daily pages.
Note how simple it is for a listener of any age or education to correctly indicate what they listened to throughout the day.