The 'expert' in problem-based and case-based learning: necessary or not?

BACKGROUND: Problem-based learning (PBL) and other small-group teaching methods which incorporate principles of adult learning, are exciting innovations in medical education. In the application of these methods to medical curricula many schools have introduced non-expert tutors. However, research evaluating the effectiveness of non-expert lead teaching has been inconclusive. AIM: The present study aim was to compare the outcome of teaching in small groups facilitated by either an 'expert' or a 'non-expert' tutor, in a single topic area. METHOD: Fourth-year medical students were allocated randomly to teaching of eating disorders either by a non-expert or an expert tutor. Outcomes were evaluated by (i) a knowledge test, and (ii) self-report ratings by tutors and students of their learning methods and other qualities. RESULTS: The study found that while the non-expert tutor was rated more highly for her group management skills, and she also rated her students more highly in the area of oral communication, students who were taught by the expert scored higher in the end-of-course test in the topic area. CONCLUSION: The findings suggest that caution should be exercised, and the need for more research before widespread adoption of teaching by non-expert tutors.