Information gathering and integration as sources of error in diagnostic decision making.

This research examined the relative importance of information gathering versus information utilization in accounting for errors in diagnostic decision making. Two experiments compared physicians' performances under two conditions: one in which they gathered a limited amount of diagnostic information and then integrated it before making a decision, and the other in which they were given all the diagnostic information and needed only to integrate it. The physicians: 1) frequently failed to select normatively optimal information in both experimental conditions; 2) were more confident about the correctness of their information selection when their task was limited to information integration than when it also included information gathering; and 3) made diagnoses in substantial agreement with those indicated by applying normative procedures to the same data. Physicians appear to have difficulties recognizing the diagnosticity of information, which often results in decisions that are pseudodiagnostic or based on diagnostically worthless information.