Content area
Abstract
Inconsistent findings comparing the relative efficacy of problem-based (PBL) versus lecture-based (LBL) learning in medical education motivated this study. In this meta-analysis of 82 studies involving 45 universities in twelve countries, with 12,979 participants and 121 findings, PBL was associated with a significant positive effect size for clinical science achievement, problem-solving achievement, self-directed learning skills, and attitude toward learning. Instructional effects were statistically equivalent for biomedical science achievement. However, variance analysis revealed a subgroup exhibiting a small, but significant positive effect size when biomedical science achievement was compared using criterion-referenced rather than standardized assessments. Findings suggest that when achievement and problem solving ability are examined with assessments contextually framed and requiring the integration and application of biomedical and clinical science knowledge, medical students and physicians who undergo PBL significantly outperform counterparts who undergo LBL. Moreover, given the dominant factual and abstract nature of the content, the lack of unique superiority of LBL for biomedical science achievement is an important practical finding. Indeed, differential instruction efficacy for clinical science and problem solving achievement imply biomedical science knowledge constructed in a PBL environment is organized for better deployment.
Current findings suggest the success of PBL is not limited to a particular approach. The advocates of PBL make some substantive claims, using ill-structured problems, using re-iterative methods, and so on, yet none of these claims were found uniquely to predict the instructional effect on cognitive outcomes. Instances of multicolinearity, however, suggest some substantive features may converge efficaciously as a function of context and desired cognitive outcome. Despite diverse methods of PBL implementation, problem posing and integration of biomedical and clinical sciences in a tutorial-group setting are common threads. Since direct instruction also can integrate biomedical and clinical sciences, further research is required to examine the unique contribution of small-group learning. Since the ultimate aim of medical education is to graduate competent clinicians who are expert learners and problem solvers, examining what distinguishes the structure and function of medical knowledge acquired when undergoing PBL versus LBL may be more insightful for informing theory and practice than global contrasts of cognitive and non-cognitive outcomes.
