The basic point is still worthwhile: predictions about other people also reveal something about yourself.
The naive implementation could end up punishing honest participants, but slightly more sophisticated methods promote honesty. Bayesian truth serum (mentioned a couple times already) does this through payments to and from survey participants. Payments can also be socially inappropriate, so finding more practical and acceptable methods is an active area of research.
The basic point is still worthwhile: predictions about other people also reveal something about yourself.
The naive implementation could end up punishing honest participants, but slightly more sophisticated methods promote honesty. Bayesian truth serum (mentioned a couple times already) does this through payments to and from survey participants. Payments can also be socially inappropriate, so finding more practical and acceptable methods is an active area of research.