Most people recognize the importance of medical education as an integral cornerstone of quality health care. It is not surprising that a considerable amount of research has been devoted to how best to train physicians. For many years, medical educators believed that physicians used hypothetico-deductive reasoning in medical problem solving and arriving at clinical diagnosis [1]. Hypothetico-deductive reasoning, also referred to as backward reasoning, is a method of eliminating hypotheses (hunches that maybe either true or false) one by one through the use of various tests, such as questions from a medical history, results of a physical examination and the outcomes of various diagnostic analyses. This is the identical process used by the scientific community for generating new knowledge where the process is known as the scientific method. Since physicians were believed to use hypothetico-deductive reasoning, this was the recommended methodology for training medical students for many years [2].
Groen and Patel were one of the first to question the idea that expert physicians use hypothetico-deductive reasoning in routine medical problem solving. They asserted that the conclusion was not justified by empirical evidence but favored because it is the standard procedure of the scientific method. They believed that the evidence from research in cognitive psychology on expert-novice comparisons indicated that the use of the hypothetico-deductive method is a characteristic of novices rather than experts.
Bordage studied the evolution of knowledge organization in novice and expert medical students and found significant differences. Novice students may have abundant knowledge, but they have not developed enough meaningful connections. They typically take prolonged history and physical exams but often miss the obvious diagnosis. As students become more experienced, histories, physicals and case presentations are more focused and pertinent and these students demonstrates accurate resolution of complex problems about 75% to 80% of the time. The most sophisticated students used patterns to search for missing elements to confirm diagnosis.
An outstanding study was conducted a few years ago at the University of Calgary by Dr. Sylvain Paul Coderre and associates which used think-aloud protocols to determine the diagnostic reasoning of experts and non-experts when attempting to diagnose clinical presentations in gastroenterology [5]. Logistic regression analysis of the results showed that there was a high correlation between the diagnostic reasoning process used and the likelihood of diagnostic success. Coderre found that hypothetico-deductive reasoning was used predominately by novices. Experienced diagnosticians only used that method when faced with a particularly complex problem or when faced with clinical problems outside their area of expertise. Many experts used scheme-inductive reasoning for reaching diagnoses. Schemes are defined as a mental categorization of knowledge, often depicted as a decision tree. Decisions are made at the branching of the tree using crucial tests, to eliminate possibilities and eventually adopt the choice left. The reasoning moves in a forward direction and results in a more focused and efficient problem solving methodology than hypothetico-deductive reasoning. The most sophisticated diagnosticians, however, used pattern recognition. Their extensive experience lead to the acquisition of a repertoire of patterns that permitted problem resolution by recognition of new problems as similar or identical to old ones already solved, and the solutions are simply recalled.
All three models of reasoning require a hypothesis evoking process. However, the method used for selection of the hypothesis to be tested differs in novices and experts. The most adequate method is selected on the basis of the practitioner’s experience in that domain and the knowledge required by the method. This research shows the interrelationship between skills and domain knowledge and also implies that development of expertise can not be analyzed independently from development of a particular type of memory scheme that facilitates solution recognition. Medicine is not unique. Strategy formulation also requires a type of diagnosis based on conceptual knowledge to characterize or understand a situation and act upon it in an appropriate way. This research has significant implications for strategy education and has influenced our methodology for teaching strategy at The Strategy Praxis™ Institute.
[1] Elstein. A., Shulman. L., Spratka. S ., Medical Problem Solving: An Analysis Of Clinical Reasoning. Harvard University Press. 1978, p. 250.
[2] Kassirer, J. Teaching Clinical Medicine by Iterative Hypothesis Testing: Let's Preach What We Practice. New England Journal of Medicine. 309, 1983, p. 921-923.
[3] Groen. G. and Patel. V. Medical Problem-solving: Some Questionable Assumptions. Medical Education. 19, 1985, 95-100.
[4] Bordage. G., Elaborated Knowledge: A Key to Successful Diagnostic Thinking. Academic Medicine. 69, 1994, p. 883-885.
[5] Coderre S., Mandin H., Harasym P., Fick G.H., Diagnostic reasoning strategies and diagnostic success. Medical Education 37(8), 2003, p. 695-703.
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- Strategy Praxis™
- The Strategy Praxis™ Institute is a research and educational organization dedicated exclusively to the advancement of strategy. The Strategy Praxis™ Institute offers pragmatic, results-oriented, client-centered programs on all aspects of strategy. Strategy Praxis™ refers to the comprehensive system for strategy formulation, implementation and assessment developed by the Institute. The goal is to assist practitioners in doing strategy in real life where the stakes are high, information often inadequate, conditions constantly shifting and the consequences of actions uncertain.
