HYPOTHESIS GENERATION AND THE COORDINATION OF THEORY AND EVIDENCE IN NOVICE DIAGNOSTIC REASONING

This study investigates hypothesis generation and evaluation in clinic al problem solving by medical trainees. The study focuses on 1) direct ionality of reasoning and 2) use of confirmation and disconfirmation s trategies in generating and evaluating hypotheses. Two clinical proble ms were divided into segments of information containing presenting com plaint, past history, and physical examination. The initial informatio n indicated a typical myocardial infarct but subsequent information co ntradicted it. The results showed that the participating students pred ominantly used forward reasoning and confirmation strategies. When fac ed with contradictory evidence: 1) second-year students ignored cues i n the problem or reinterpreted them to f it the hypothesis; 2) third-y ear students generated concurrent hypotheses to account for different sets of data; and 3) fourth-year students generated several initial hy potheses and subsequently narrowed the hypothesis space by generating a single coherent diagnostic explanation. The results are discussed in terms of coordination of clinical evidence and its relationship to sc ientific reasoning.