Problem-based Learning (PBL)

January 15, 2020
Last updated October 20, 2022


Problem-based learning (PBL) is an instructional method that was originally developed by Howard Barrows at McMaster University in the 1980s to teach diagnostic skills using patient problems. As the problem (case) is explored, more information is revealed such as patient laboratory results or radiographic images. In the classroom, the problem unfolds over several days or in several stages. In each stage, through the use of whiteboards and other research resources, learners engage in a defined set of activities related to the problem.  Students extract, discuss, identify, and record the details of the case with the following organizing headings:

  1. Facts
  2. Hypothesis
  3. More Information Needed
  4. Learning Issues
Instructor Role

The instructor in PBL is often referred to as a tutor or facilitator. The facilitator has a limited role in that facilitation is comprised of ensuring students follow the PBL process, asking students probing questions, and keeping the students on track working through the facts, hypotheses, identifying information needed, and recording new learning issues. The instructor may have responsibility for the design of PBL case problems. 

The instructor does not lecture, provide information or answers when students get stuck or, perhaps, as students explore potentially incorrect diagnoses. If PBL occurs over multiple meetings or class sessions, students walk away with topics they have to research “learning issues."  When they return for the next class, these topics are presented orally (with or without supporting materials); thus, adding to the group’s understanding.  At the end of the case, the students and faculty debrief on the group process, and review and discuss “expert” case summaries.  The final case summary provides the “expert” physician’s treatment plan, and also may clarify any remaining gaps in knowledge. Finally, students may be directed to additional resources related to the case topic, or problem.  On a continuum of instructional guidance from low guidance to high guidance, PBL is an instructional method that, if implemented as designed, requires a low level of active instructional guidance (Figure 1).

Figure 1. Instructional Guidance Level Needed

Low guidance                                                                            High guidance


Learner Role

In a typical PBL case, students are assigned different roles such as reader, scribe or recorder, and PBL monitor. The reader (or readers, if students rotate this responsibility) read the case materials out loud, while other members of the group actively listen. Students may follow along the reader viewing text on paper, on screens, or on a projection from a device.

Once the reader completes reading aloud, a scribe or recorder will go to the board and begin writing down the facts of the case, as students call them out. For example, Student A states, this is a “12 year-old, Hispanic female, 72 pounds, a fever of 102 degrees, coughing, brought to ER by mother.” When all relevant facts available in the case materials are recorded, the monitor may ask students “What are the initial hypotheses?"  Or “Are we ready to move on?”  The step the students take next is often determined by their level of competence or stage in the curriculum. For example, if students are in the second year of a preclinical medical curriculum, then they may be more adept at the process than a first-year, first-semester medical student. On a continuum of engagement and learner activity from low to high, PBL requires students learn differently. Students are very central and active architects of their own understanding and learning (Figure 2).


Figure 2. Learner Activity Level Required

Low engagement                                                                    High engagement


How to do it?

Instructors should clearly determine the learning goals guiding engagement in PBL. For example, medical schools have integrated PBL into an overall curriculum strategy, where many groups of students in many classrooms experience PBL simultaneously. Typically, PBL groups should include six to eight students and a single faculty facilitator. Schools implementing PBL on this scale should be clear on the resources required for such use. Once PBL is selected as a strategy, the classroom experience looks like this: PBL is often used in clinical, education, business, and health professions classrooms, as these professions are most suited to the case problem format.   

Assessment of PBL

PBL assessments may include a variety of approaches. The aim of any assessment of PBL instruction should be geared toward development of several key outcomes: decision-making, critical analysis, diagnostic reasoning skills, collaborative group work and process, and individual research skills.  Schools have approached assessment in a variety of ways, with most often being an independent case assessment where students must engage the diagnostic reasoning skills learned through PBL to complete a paper-based assessment.  Faculty evaluations of group process, presentation skills rubrics (for learning issue presentations), and peer review may also be used. Instructors should avoid a single assessment measure as an indication that learning through PBL has occurred.

Online Options

PBL has been explored in the online and distance education context for about 15 years (2004).  While it can be challenging for the novice instructor to design, those who have face-to-face PBL experience may find this more palatable.  For example, cases can be presented via video and role plays, patient simulations and asynchronous discussion boards follow the same sections over stages of case problems, as in person. See Savin-Baden, M., & Wilkie, K. (2006) for a comprehensive resource.

Instructional Classroom Time

90 minutes to two hours per session

Other resources
  1. Albanese, M.A., & Mitchell, S. (1993). Problem-based learning: A review of literature on its outcomes and implementation issues. Academic Medicine, 68, 52-81.
  2. Barrows, H.S. (1985) How to design a problem-based curriculum for the preclinical years. Springer, New York.
  3. Barrows, H.S. (1986) A taxonomy of problem-based learning methods. Medical Education, 20, 481–486.
  4. Dochy, F., Segers, M., Van den Bossche, P., & Gijbels, D. (2003). Effects of problem-based learning: A meta-analysis. Learning and instruction, 13(5), 533-568.
  5. Koh, G. C. H., Khoo, H. E., Wong, M. L., & Koh, D. (2008). The effects of problem-based learning during medical school on physician competency: a systematic review. Cmaj, 178(1), 34-41.
  6. Norman, G. T., & Schmidt, H. G. (1992). The psychological basis of problem-based learning: A review of the evidence. Academic medicine, 67(9), 557-565.
  7. 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.
  8. Savin-Baden, M., & Wilkie, K. (2006). Problem-based learning online. McGraw-Hill Education (UK).

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Problem-based Learning by Christina Cestone is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

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