The aim of this article is to examine processes occurring within problem-based learning (PBL) courses (inside the black box) by contrasting these processes with outcome-based studies (from outside the black box). We review meta-analyses of input–output studies of PBL in comparison with traditional approaches and provide a summary of qualitative, phenomenographic and factor analytic analyses of student experiences when studying health sciences (dentistry and medicine) using PBL curricula. Results from metaanalyses
showed PBL courses were preferred for the long-term retention of course content, short-term retention involving elaboration of new information and the application of clinical skills and reasoning. Traditional approaches were favoured for short-term retention of course content that did not require any elaboration. The qualitative studies reveal a diversity of student views about the concept of PBL pedagogy and approaches to learning in PBL curricula. They show that the ways in which students approach their studies in PBL in health sciences are closely related to how they conceive of PBL and that these dimensions are closely related to how the goals and standards of PBL courses are perceived.