On the calibration of knowledge and perception.

This study examined confidence judgements (i.e., calibration, resolution, and over/underconfidence) and response times in an intellectual knowledge task and a perceptual task requiring location comparisons. At each of four levels of judgement difficulty (i.e., Easy, Hard, Impossible and Misleading/Illusory), very similar properties were evident in the two tasks. The results are inconsistent with theories that assume a fundamentally different basis for confidence in human knowledge and perception.