Problem‐based learning: a coat of many colours

Problem-based learning, as an educational approach, is growing worldwide. At the recent Changing to PBL conference at Brunel University, participants from around the world met to discuss the strategies, implications and consequences of implementing problembased courses. The strong international representation attending con®rmed PBL as `an idea whose time has come' (Bligh 1995). Equally impressive was the range of disciplines and professions that have adopted PBL as an educational approach. Although PBL is well established in health care education, papers were also presented from architecture, engineering, law, the police and the natural sciences. The conference therefore provided a unique opportunity for the proponents of PBL to exchange news and views on practice as well as theory. What emerged from the conference, apart from the enthusiasm, was the realization that PBL is interpreted in widely different ways. PBL in action is currently characterized by many different strategies. What is happening at the coalface in Liverpool may be quite distinct from that at Southern Illinois, Maastricht or Flinders. This variety has important consequences for evaluation and research since ®ndings from one PBL institution may not be applicable or relevant to another also employing the problem-based approach. The same caution applies to comparisons with other types of curricula. It would appear likely that the two major meta-evaluations ± Albanese & Mitchell (1993) and Vernon & Blake (1993) ± have been confounded by exactly this problem. In fact, Albanese & Mitchell (1993) do discuss some of the possible variables, stating unequivocally in their conclusion that `future research should attempt to document more concretely the types of PBL approaches being used in the various curricula'. Apart from Barrows' taxonomy of problem-based learning methods (Barrows 1986), there is no systematic classi®cation of PBL methodology. This taxonomy assumes that PBL is not a unity, but more a broad church with a common creed uniting distinct denominations. Barrows takes four educational objectives as the starting point: the development of clinical reasoning and self-directed learning skills, the importance of learning to structure knowledge for use in clinical contexts, and increased motivation dependent upon the ®rst three objectives. The most signi®cant variables upon outcome are the type of problem, the learning sequence, the degree of self-directed learning and assessment procedures. To achieve the stated objectives of the strongest variant, namely closed-loop or reiterative problem-based learning, problems should be functionally appropriate, be delivered before any other learning materials, teacher direction should be minimized, and the full range of objectives rather than only factual content must be assessed. Although not spelt out, it is clear from the list that educational process is valued above content. There is a danger, though, of negating the holistic nature of learning central to PBL if the orthodoxy of process is to replace the orthodoxy of content (Margetson 1997). How do these aims compare with current practice? None would disagree that the problem or trigger is the cornerstone of PBL and that it should initiate and direct the student's learning, but subtle differences have developed in several areas. These relate to the type of trigger used, the practical interpretation of `self-directed', and the content/process dichotomy.