ORDER OF INFORMATION AFFECTS CLINICAL JUDGMENT

Family practice physicians read a case vignette describing a patient w ith a history of lung cancer, a new transient neurological disturbance , and a normal computerized tomographic (CT) scan of the head. They th en estimated the probabilities of two diagnoses: transient ischemic at tack (TIA) and brain tumor. Probability estimates of TIA were lower if the history of lung cancer was presented at the end of the case rathe r than at the beginning. This recency effect was found for both more a nd less experienced physicians and whether subjects were prompted for a single end-of-sequence probability judgment or multiple step-by-step judgments after each piece of information. These results are inconsis tent with Hogarth and Einhorn's (1992) belief-adjustment model, which predicts a recency effect for the step-by-step condition but a primacy effect for the end-of-sequence condition.