Experimental studies of learning dermatologic diagnosis: The impact of examples

Two experiments investigate the role of examples in learning dermatologic diagnosis. Medical students were given a written set of normative rules for the diagnosis of six common skin disorders, followed by practice applying those rules to a set of photographic images. On subsequent testing, the accuracy of diagnosing a set of critical new items depended strongly on the diagnosis of the most similar practice item, even when the test item was typical of its disorder. This suggests that the effect of the practice items was not restricted to providing practice in applying the rules. The influence of similar practice items persisted after a week between practice and test. The implication is that exposure to many examples may be a critical component of clinical reasoning.