Overconfident behavioral predictions and trait inferences may occur because people make inadequate allowance for the uncertainties of situational construal. In Studies 1–3, Ss estimated how much time or money they would spend in various hypothetical, incompletely specified situations. Ss then offered associated “confidence limits” under different “construal conditions.” In Study 4, Ss made trait inferences about someone they believed had responded “deviantly,” again with situational details unspecified and construal conditions manipulated. In all 4 studies, Ss who made predictions or trait inferences without being able to assume the accuracy of their situational construals offered confidence limits no broader than those of Ss who made their responses contingent on such accuracy. Only in conditions where Ss were obliged to offer alternative construals did they appropriately broaden their confidence limits or weaken their trait inferences.