Answer to "Who developed PBL and why?"

PBL was conceptualised by Barrows and Tamblyn and implemented in the medical programme at McMaster University in 1968 after several years of development. In the context of a small group guided by a tutor, PBL was envisaged as a curriculum approach for the pre-clinical phase of graduate-entry medicine. Its purpose was to mirror what happens in clinical practice when newly graduated doctors with limited experience encounter patients (i.e. work through the available evidence, recognising their own limitations which then trigger research and learning). In working through ‘ill-structured’ or messy ‘problems’, the PBL process was designed, through a series of steps (e.g. brainstorming, activation of prior knowledge and experience), to engage learners in hypothetico-deductive reasoning (mirrors clinical reasoning) to develop a list of ranked hypotheses about what might be happening to the patient. In so doing, they would generate a list of learning issues (i.e. gaps in their understanding) to resolve the ‘problem’. This PBL process takes place in three phases (and several steps):

  • Phase 1 (‘problem’ encountered): In small groups, discussion is triggered by a clinical ‘problem’ prior to any specific study, requiring activation of prior knowledge, hypothesis generation and identification of gaps (learning issues) (Steps 1-5)

  • Phase 2 (self-study): A period of self-study during which students address the learning issues they identified through research (Step 6)

  • Phase 3 (reporting): Groups then reconvene a few days later to fully explain and elaborate on what might be underlying the patient’s presentation, i.e. apply their knowledge and refute or confirm their hypotheses (Step 7).


These steps reflect Maastricht University’s Seven-Jump Model of the PBL process:

  1. Clarify unknown terms and concepts in the ‘problem’ description

  2. Define the problem, i.e. list the phenomena to be explained

  3. Analyse the problem: Brainstorm and produce as many different explanations as possible for the phenomena using prior knowledge and rationale thinking (i.e. generate hypotheses)

  4. Critique the proposed explanations and try to produce a coherent description of the processes underlying the phenomena

  5. Formulate learning issues to address gaps in knowledge or understanding

  6. Through a period of self-study, research the required information to address the learning issues

  7. Return to the PBL group and share findings and integrate the newly acquired knowledge into a comprehensive explanation of the phenomena. This reporting back phase should allow for inconsistencies to be ironed out and for learners to gauge whether they have covered the expected depth and breadth.



BARROW, H.S., and TAMBLYN, R.M. (1980). Problem-based Learning: An Approach to Learning. (New York: Springer).

BARROWS, H.S. (1992). The Tutorial Process. (Springfield: Southern Illinois University).

Maastricht University website:

TAYLOR, D., and MIFLIN, B. (2008). AMEE Guide No. 36. Problem-based learning: Where are we now? (Med Teach. 30:742-763).

SCHMIDT, H.G. (1983). Problem-based learning: rationale and description. (Med Educ. 17(1):11-16).