The Perceived Informativeness of Factual Information

Subjects told the correct answer to two-alternative general knowledge questions e.g., Absinthe is 1 a precious stone, or 2 a liqueur were found to overestimate both the likelihood that they would have known the answer had they not been told and the likelihood that they did know the correct answer before being told. Attempts to undo this knew-it-all-along effect by exhorting subjects to work harder or telling them about it failed. These results were discussed as representative of those obtained in a general class of tasks in which people are called upon to disregard information which they have already processed.