Problem-Based Learning (PBL) 

What is it? 

Introduced by Barrows and colleagues at McMasters University in 1969, PBL has been heavily used in medical education, expanding to science and engineering, and arts and humanities disciplines (Allen, Donham, & Bernhardt, 2011). It harnesses small group work to engage students in self-directed learning, based around a case, which students generate their own learning goals (‘issues’) from. The teacher acts as a facilitator, scaffolding the learning process.  

The process differs from problem-solving in the sense that the latter could incorporate teacher-defined theoretical conceptual problems (e.g. worked examples) as opposed to authentic real-world problems that professionals would be expected to encounter in the workplace, which students are required to solve in a self-directed, collaborative way. Although PBL is based around a case, it differs from case-based learning, and is also distinct from enquiry-based learning (Savery, 2006). 

How does it work? 

In reflecting on the development of PBL, Barrows (1996) outlined the components of ‘pure’ PBL: 

  1. Student-centred learning 
  1. Small group learning 
  1. Teachers as facilitators 
  1. Using problems to develop problem-solving skills; in this context of medical education, these are clinical cases 
  1. Acquisition of new knowledge through self-directed learning 

Students meet as a group with their facilitator, to review the case and identify areas of enquiry. They then research aspects of the case individually and/or collaboratively, outside the classroom, before bringing their knowledge back to another small group class to share with each other and the facilitator, resulting in new lines of enquiry being generated to be resolved in the second class. Typically, one student leads the discussions and another acts as scribe for the group. 

Variations of PBL exist; Barrows (1986) attempted to create a taxonomy of these, representing variations in the way student are primed to solve the problem (e.g. lecture or case-primed), the extent to which the session is teacher- or student-led, and the sequence of learning activities. At UofG medical school, the GLASGOW steps are employed to guide students (Prof. Susan Jamieson, personal communication), based on Schmidt’s (1983) seven-step strategy: 

  • First one-hour tutorial: 
    • Grasp (read) the scenario and define words you do not understand 
    • List the main issues in the scenario 
    • Activate your mind (brainstorming of existing knowledge and gaps) 
    • Set questions to be addressed (the learning goals) 
    • Got what you need (plan resources; publications or experts to consult) 
  • Two to three days of independent enquiry 
  • Second one-hour tutorial: 
    • Offer your answers (feedback) 
    • What’s our role in this? (reflection on group performance) 

The term ‘tutorial’ is slightly misleading in that the class is learner-centred rather than teacher-centred, though this is the term employed by Barrows. 

Does it work? 

Several systematic reviews and meta-analyses have been conducted to examine the effectiveness of PBL, with mixed results (Allen et al., 2011). In his appraisal of previous conflicting reviews, Neville (2009) highlighted that despite the methodological challenges of aggregating findings from different reviews, some conclusions could be drawn; PBL is less good for knowledge retention but better for knowledge application and the development of clinical competencies such as dealing with uncertainty, communication skills and self-directed learning.  

A systematic review of 39 studies by Polyzois, Claffey and Mattheos (2010) revealed largely negative outcomes of comparing the impact of PBL versus traditional teaching on student performance using Randomised Control Trials (RCTs). As in Neville’s (2009) review, Polyzois et al. (2010) noted poorer performance in knowledge recall; however, they argued that multiple-choice questions (MCQs) are an inappropriate form of assessment for PBL. Comparative studies were more promising, with PBL resulting in better clinical reasoning and problem-solving and a more enjoyable approach to learning (Polyzois et al. 2010). Interestingly, the authors observed that more positive gains were observed from single PBL interventions as opposed to entire PBL curricula, which could reflect the novelty of individual instances of PBL. 

What do I need? 

Unlike SCALE-UP or team-based learning, PBL is based on small group classes of 5-9 students; this means that larger classes need to be co-scheduled in adjacent seminar rooms, and/or timetabled over different sessions.  

The tables are usually arranged boardroom style, and a whiteboard is an essential element in the room, to allow the student acting as scribe to take notes as students engage in identifying their learning goals and the problem-solving process. 

To ensure curriculum coverage, Barrows (1996) suggests development of a curriculum ‘matrix’, with intended learning outcomes along one axis and cases along the other, which can be updated as new cases are introduced.  

As with other active learning techniques, it is helpful to observe a PBL session first, before running one yourself, or speak with staff experienced in PBL. Academic staff who can help include: Dr Joanne Burke and Dr Carol Ditchfield, recipients of a University Teaching Excellence Award for introducing PBL at the medical school, who facilitate PBL sessions. 


A video of the stages of PBL by Dr Carol Ditchfield and Dr Genevieve Stapleton in the School of Medicine, Dentistry and Nursing at UofG

Another video of PBL at the University of Illinois medical school similarly shows the stages of PBL in action. 


Allen, D. E., Donham, R. S., & Bernhardt, S. A. (2011). Problem‐based learning. New Directions for Teaching and Learning, 2011(128), 21-29.  

Barrows, H. S. (1986). A taxonomy of problem‐based learning methods. Medical Education, 20(6), 481-486.  

Barrows, H. S. (1996). Problem‐based learning in medicine and beyond: A brief overview. New Directions for Teaching and Learning, 1996(68), 3-12.  

Neville, A. J. (2009). Problem-based learning and medical education forty years on. Medical Principles and Practice, 18(1), 1-9.  

Polyzois, I., Claffey, N., & Mattheos, N. (2010). Problem‐based learning in academic health education. A systematic literature review. European Journal of Dental Education, 14(1), 55-64.  

Savery, J. R. (2006). Overview of problem-based learning: definition and distinctions. The Interdisciplinary Journal of Problem-based learning, 1(1), 9-20.  

Schmidt, H. G. (1983). Problem-based learning: rationale and description. Medical Education, 17(1), 11-16. doi:10.1111/j.1365-2923.1983.tb01086.x 

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