Analysis of problem-solving strategies reveals that although there is no universal, generic problem-solving process, there is a clinical reasoning process that is specific and highly tailored to the complexity of each clinical problem. Research reveals that successful problem solvers must possess comprehensive knowledge, but that the way they organize and understand their knowledge is even more critical. Moreover, using "schemes" for both learning and problem solving provides the advantage of combining the creation of a knowledge structure and a search-and-retrieval strategy into a single operation. (A "scheme" in this context is a mental categorization of knowledge that includes a particular organized way of understanding and responding to a complex situation.) The implication for medical education is that a comprehensive knowledge domain must be appropriately organized for knowledge mastery, which in turn is essential for clinical problem solving. Problem-solving strategies must be specific for each problem and not based on the assumption of a universal generic process. Consequently, a new taxonomy of medical problems is recommended, along with an altered problem-based learning (PBL) format. The "hypothetico-deductive" strategy traditionally used in PBL should be replaced by scheme-driven search strategies so that students develop a more organized and logical approach to problem solving.