Outcome Feedback Effects on Under- and Overconfident Judgments (General Knowledge Tasks)

Abstract

Effects of outcome feedback on overconfident and underconfident judgments were investigated. It was hypothesized that outcome feedback had a twofold effect on confidence judgments, corrective and confidence increasing, the latter effect operating only when the items to be judged are related and/or nonindependent. The proposed hypothesis implies two predictions which were tested in two experiments: (1) If the items are nonindependent and related, outcome feedback will reduce bias and improve calibration of underconfident judgments; by contrast, the feedback will neither reduce bias nor improve calibration in the case of overconfident judgments. (2) If, on the other hand, the items are independent and unrelated, outcome feedback will reduce underconfidence as well as overconfidence bias and improve calibration in both cases. The obtained results provided strong support for the first prediction, while the second prediction was not supported. Although the differences between with- and without-feedback groups on the dependent variables were in the expected direction, they were nonsignificant.