EDUCATIONAL PSYCHOLOGIST, 44(4), 227–249, 2009 Copyright C  Division 15, American Psychological Association ISSN: 0046-1520 print / 1532-6985 online DOI: 10.1080/00461520903213592 Constructivist, Problem-Based Learning Does Work: A Meta-Analysis of Curricular Comparisons Involving a Single Medical School Henk G. Schmidt, Henk T. van der Molen, and Wilco W. R. te Winkel Department of Psychology Erasmus University, The Netherlands Wynand H. F. W. Wijnen Department of Educational Development and Research Maastricht University, The Netherlands Effects of problem-based learning as reported in curricular comparison studies have been shown to be inconsistent over different medical schools. Therefore, we decided to summarize effects of a single well-established problem-based curriculum rather than to add up sometimes- conflicting findings from different problem-based curricula. Effect sizes were computed for 270 comparisons. The results suggest that students and graduates from the particular curriculum perform much better in the area of interpersonal skills, and with regard to practical medical skills. In addition, they consistently rate the quality of the curriculum as higher. Moreover, fewer students drop out, and those surviving need less time to graduate. Differences with respect to medical knowledge and diagnostic reasoning were on average positive but small. These outcomes are at variance with expectations voiced in recent contributions to the literature. They demonstrate that constructivist curricula can have positive effects on learning even if they deemphasize direct instruction. In 1969, a first group of 20 medical students arrived at McMaster University, Hamilton, Ontario, to enroll in a cur- riculum that was quite avant-garde, even by international standards. Students engaged in a process of learning and in- struction that was called “problem-based learning” (PBL). They were to work on relevant biomedical or clinical prob- lems in collaboration with peers and guided by a tutor. The number of lectures they received each week was lim- ited to one or two. Students were supposed to learn pri- marily through self-directed study, guided by the problems designed by their teachers (Hamilton, 1976; Neufeld & Bar- rows, 1974). In addition, the curriculum emphasized the ac- quisition of medical, interpersonal, and other professional competencies. Would the early developers at the time have had the appropriate terminology available, they would have described their curriculum as constructivist, promoting con- Correspondence should be addressed to Henk Schmidt, Department of Psychology, Erasmus University, P.O. Box 1738, 3000 DR Rotterdam, The Netherlands. E-mail: schmidt@fsw.eur.nl textual, collaborative learning, self-regulation, and student agency (Brown, Collins, & Duguid, 1989; E. Cohen, 1994; Scardamalia & Bereiter, 1991). Now, 40 years later, there is little doubt that PBL is quite popular as a pedagogical innovation, in particular in medical education. For example, a majority of the medi- cal schools in the United States includes small-group tuto- rial sessions organized around clinical problems, and 20% of these consider themselves to be problem-based outright (Association of American Medical Colleges, 2005). In addi- tion, most Australian medical schools have adopted PBL as their instructional method (Sanson-Fisher & Lynagh, 2005), and curricula based on these ideas have also been devel- oped in Europe and Asia (e.g., Antepohl & Herzig, 1999; Fyrenius, Silen, & Wirell, 2007; Khoo, 2003; O’Neill, Mor- ris, & Baxter, 2000; Tiwari, Lai, So, & Yuen, 2006). More- over, PBL has been adopted in economics and business (Gi- jselaers et al., 1995), engineering (Dahlgren & Dahlgren, 2002), psychology (Reynolds, 1997), law (Moust & Nuy, 1987), and biology (Kendler & Grove, 2004). Finally, PBL Downloaded By: [Erasmus University Library / Rotterdamsch Leeskabinet / Erasmus MC / Univ Med Centre Rotterdam] At: 11:55 22 December 2009