Expert-novice differences in clinical decision making

This paper reviews the cognitive science literature on expertise and presents methodology designed to examine expert-novice differences in the domain of clinical (psychology/psychiatric) diagnosis. The study examines differences between experienced and novice clinicians on a clinical diagnostic task. 10 novice psychology graduate students and 9 experienced psychologists read two case histories, each divided into a series of clinical vignettes. Subjects were asked to "think aloud" about the case formulation and later asked to recall of information about the case. Recorded protocols were transcribed and coded according to frequencies of diagnostic hypotheses, symptom hypotheses, speculative ideas, case references, and case features. Results showed significant differences between experienced and novice subjects' use of diagnostic and symptom hypotheses. Experienced subjects also generated a greater proportion of case reference to case feature statements. No differences were found in case information recalled. These results support predictions generated from a cognitive representation model of expertise.