It has long been assumed that Part 3 of the National Boards, which stresses patient management and clinical problems, is a valid measure of "clinical competence" for doctors. These authors, challenging this premise, devised a study to analyze which components of medical school achievement are most predictive of Part 3 performance. Their correlation matrix incorporated 46 computer generated variables. Subjects were 152 students attending Jefferson Medical College who had completed all three examinations as candidates for National Board certification. Results showed that 15 measures had a significant relationship with Part 3 performance. The authors found that measures of factual medical knowledge were better predictors of Part 3 performance than were performance-oriented or computer-referenced measures and agreed with previous researchers that patient managemental problem measures, though intuitively appealing, are found both weak and ambiguous when subjected to rigorous statistical analysis. (BJG)