[msg]

For $50? College students have done much weirder and stupider stuff for less money than flipping a coin twice and answering a straightforward T/F question, even if it were twenty questions. The technique has been around for a long time. You should consider it a solved problem.

Finally googled the names. I also discovered the original formulations do it with only one coin flip (or one roll of a die).

http://en.wikipedia.org/wiki/Randomized_response

http://en.wikipedia.org/wiki/Unmatched_count

[delinka]

If you're offering $50 in cash to answer some questions and flip some coins, sure you'd get people to answer loads of them. But you're not offering an incentive to answer the questions.