Mechanistic case diagramming: a tool for problem-based learning.

Without appropriate learning tools to guide the application of knowledge to clinical situations, medical students in a problem-based learning (PBL) curriculum may revert to traditional modes of learning and hence deprive themselves of PBL's educational benefits. The author describes a technique involving the stepwise diagramming of pathophysiologic mechanisms leading from underlying causes to the symptoms and findings presented in a PBL case. This technique can guide clinical reasoning during an initial problem encounter, the identification of pertinent learning issues, and the subsequent integration of knowledge as relevant to the patient's case. The author suggests that training students and tutors to use this technique may allow the former to fully realize the benefits of PBL, including the ability to organize information for use in clinical contexts and the ability to critically reflect upon their own learning.