In the interest of improving their decision making, individuals revise their opinions on the basis of samples of opinions obtained from others. However, such a revision process may lead decision makers to experience greater confidence in their less accurate judgments. The authors theorize that people tend to underestimate the informative value of…

Format dependence implies that assessment of the same subjective probability distribution produces different conclusions about over- or underconfidence depending on the assessment format. In 2 experiments, the authors demonstrate that the overconfidence bias that occurs when participants produce intervals for an uncertain quantity is almost…