Reasoning and Instruction in Medical Curricula

We describe two experiments that examine the knowledge and explanatory processes of students in two medical schools with different modes of instruction. One school had a conventional curriculum with basic science courses taught 11/2 years before the clinical training; the other had a problem-based learning curriculum with basic science taught in the context of clinical problems and general problem-solving strategies involving knowledge elaboration and hypothetico-deductive reasoning. Both before and after being exposed to relevant basic science information, students were asked to provide diagnostic explanations of a clinical case. in this study, students in the problem-based learning curriculum reasoned in a manner consistent with the way they were taught, using a backward directed pattern of reasoning and extensive elaborations based on detailed biomedical information. However; these students had a greater tendency to commit errors of scientific fact, to generate less coherent explanations, and to use flawed patterns of explanation, such as circular reasoning. These results are viewed as reflecting the operation of two factors: context and method of instruction. The interaction between these factors is expressed in terms of the hypothesis that basic science and clinical knowledge constitute two different worlds.