Wednesday, 30 May 2018

What is Case Based Learning (CBL), Problem Based Learning (PBL), & Scenario Based Learning (SBL)?

What are they, why use them and suggestions on how to implement.

Yesterday was a fairly quiet at the School, so I got a chance to research and write up something on case vs problem vs scenario based learning.  These are my current notes and are likely to feed into a TEL briefing, staff development session, conference or journal article.


The School is interested in developing a pedagogy that will fare well with increased student numbers and the expansion into online provision.  There is an implicit assumption that an ‘active learning’ and/or ‘student centred’ pedagogy may be most appropriate.  These approaches often use problem, scenario, or case base learning (PBL, SBL, CBL), and thus this post summarises what we know, why they may be effective, and suggests ‘good practice’ for implementation.


Case Based Learning (CBL), Problem (PBL), & Scenario (SBL) are pedagogies that outline a case, problem, or scenario, and then ask the learners to consider the scenario in the context of learning outcomes to reinforce existing knowledge and perhaps find new information that is relevant. Typically, the approach uses small groups supervised by an expert (in content & teaching) who nudges learners towards the learning outcomes. Barrows (1986) outlines a PBL spectrum with two main variables – the amount of briefing (minimal to comprehensive), and expert input (minimal to ‘directed’), and concludes: ‘The term problem-based learning must be considered a genus for which there are many species and subspecies’ (ibid, 1986:485).  Currently, PBL approaches suggest minimal briefing and guidance, allowing learners to “explore tangents” (Srinivasan, 2007:74) whilst a CBL approach suggests increased guidance, avoiding “tangents” with guided questioning (ibid).

Kirschner, Sweller & Clark, (2006:75, my bolds) identify some PBL approaches:
 “…discovery learning (Anthony, 1973; Bruner, 1961); problem-based learning (PBL; Barrows & Tamblyn, 1980; Schmidt, 1983), inquiry learning (Papert, 1980; Rutherford, 1964), experiential learning (Boud, Keogh,  &  Walker,  1985;  Kolb  &  Fry,  1975),  and constructivist learning (Jonassen, 1991; Steffe & Gale, 1995).”

Scenario based learning is less well defined – a scan of contemporary literature reveals a paucity of description of the technique (Domingos & Lee, 2015; Ozogul, 2018; Khatiban et al, 2018).

Currently, I suggest that many implementations of PBL are more like CBL, and that at the School we tend to mean CBL when we mention these approaches.


The School favours CBL because it produces a deeper learning experience where a real understanding of the issues and techniques are developed and is preferred by students and staff (Hassoulas et al., 2017; Wilkes & Srinivasan, 2017; Srinivasan, 2007).  The approach and its inherent critique of didactic approaches is perhaps best encapsulated in the phrase:

“Tell Me and I Will Forget; Show Me and I May Remember; Involve Me and I Will Understand”

… often cited as Confucius (450BC).

However, there are tensions when introducing PBL to medical education as it takes significantly longer to cover the same curriculum items vs the traditional didactic method (Wilkes & Srinivasan, 2017).  It is also resource intensive in terms of space and experts’ time (Hassoulas, et al., 2017).  Kirschner, Sweller & Clark (2006) are also critical of a PBL approach, citing Albanese and Mitchell’s (1993) study of PBL vs conventional methods that concludes that “…although PBL students receive better scores for their clinical performance…” (ibid:82), they also find:
  • Lower exam scores;
  • No differences in residency selections;
  • More study hours each day;
  • Inefficient use of tests (significantly more tests & less benefit);


For the School, I suggest:
  • A social constructivist approach via group work (6-10 members);
  • Scenarios should be written, perhaps augmented by audio / video segments;
  • Scenarios may develop as a session progresses (e.g., emergency real time role-play);
  • An expert supervises the session – perhaps one expert for 6-8 groups;
  • Experts listen in and guide learners towards learning outcomes, with guided questioning or more direct intervention to reduce ‘off piste’ exploration.

Face to face:
Problems may arise supervising groups as they may not easily corral themselves to areas convenient for supervision.  Space for these sessions will be significantly more than that required by a traditional ‘lecture’ – ideally a large space with a handful of tables set far enough apart to allow group discussion and close enough to allow expert monitoring and facilitation.

This may be an easier implementation due to moving from virtual room to room via a click (for synchronous sessions) or being able to monitor all interactions on an asynchronous discussion board.  However, more supervision and guidance will demand more attention from experts.


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

Domingos, E., & Lee, J. (2015). The evolution of scenario-based learning. In Games+ Learning+ Society Conference. Madison, Wisconsin. Retrieved from 

Hassoulas, A., Forty, E., Hoskins, M., Walters, J., & Riley, S. (2017). A case-based medical curriculum for the 21st century: The use of innovative approaches in designing and developing a case on mental health. Medical Teacher. 

Khatiban, M., Amini, R., & Farahanchi, A. (n.d.). Lecture-based versus problem- based learning in ethics education among nursing students. 

Kirschner, P. A., Sweller, J., & Clark, R. E. (2006). Why Minimal Guidance During Instruction Does Not Work. Educational Psychologist, 41(March 2015), 87–98. 

Ozogul, G. (2018). Best Practices in Engaging Online Learners Through Active and Experiential Learning Strategies. Interdisciplinary Journal of Problem-Based Learning, 12(1). 

Srinivasan, M., Wilkes, M., Stevenson, F., Nguyen, T., & Slavin, S. (2007). Comparing problem-based learning with case-based learning: Effects of a major curricular shift at two institutions. Academic Medicine. 

Wilkes, M. S., & Srinivasan, M. (2017). Problem Based Learning. In J. A. Dent, R. M. Harden, & D. Hunt (Eds.), A practical guide for medical teachers (Fifth, pp. 134–142). Edinburgh: Elsevier Churchill Livingstone. Retrieved from


Unknown said...

Interesting read David, I agree that pinning down case based learning is a lot harder than PBL. I have used both approaches over the years, I was not surprised by the outcomes of the Srinivasan et al (2007) research that showed staff and students preferred CBL (guided inquiry) over PBL (open inquiry) as in my experience it is a lot easier to support CBL as a tutor. PBL I felt took a lot more pre-design of resources etc and students need a lot more facilitation as the 'open inquiry' approach of PBL means they are a lot more likely to wander off track. Students also preferred CBL as (in my experience) they crave the structure that a CBL guided enquiry gives them (they crave structure in assessment, period!). They find PBL uncomfortable and often frustrating and often do not see the real value in PBL until well after the process is complete.

All this being said, I believe that there is real value in a mix of PBL and CBL, possibly shifting that mix as they move through their studies (although I know your students are post grad so you possibly do not have the 3 year process of development we get with undergrads). The benefits of PBL come from the students being pushed out of their comfort zone in to a space where they have to find and make sense of the knowledge themselves and apply it to the problem they have been set, it develops self-sufficiency and creativity but they often find it frustrating and difficult. In my opinion, we learn and develop when we are pushed outside our comfort zone, which PBL does. So I feel asking staff and students to identify what they preferred of the two in the above mentioned study was a foregone conclusion, and slightly unfair to PBL as its very purpose is to put students in to a space where they have to find their own way, ultimately making them less comfortable!

I used CBL a lot and can see the value of the structured approach for staff and students that it brings, it is also great as an authentic assessment tool. But these kinds of thoughts always bring me back to the problems with our evaluation of learning and 'student satisfaction' as I feel what we currently ask (although implicitly) is how 'comfortable' students were during the process, but discomfort at the edge of the zone of proximal development is a powerful learning tool, but it does create discomfort, which often translates in to lower 'satisfaction' scores! I'll stop blathering on now :)
Thanks for your post,

David Callaghan said...

Fab comments Claire - I had missed the bias that asking about 'comfort' brings - and that PBL is inherently more uncomfortable, plus P{BL places learners in perhaps the most efficient place to learn - their ZPD (Vygotsky) - or does ZPD hint towards CBL?
Many thanks for your contribution - worth a tweet I think.
Very kindest regards, David

Unknown said...

Thanks David, I think both PBL and CBL can place students in the ZPD (if done correctly!) just that students find CBL more supportive/structured so they find it more comfortable, or at least less scary than PBL! All just my opinion from experience I should say! :) Thanks again

Unknown said...

Thanks David,

I recently became more aware of CBR in connection with my PhD study and came across this excellent discussion of PBL and CBR:

Tawfik, A. A. , & Kolodner, J. L. (2016). Systematizing Scaffolding for Problem-Based Learning: A View from Case-Based Reasoning. Interdisciplinary Journal of Problem-Based Learning, 10(1). Available at:

We have developed a situation-based pedagogy for social work education and CPD that combines many of the ideas of PBL and CBL. If you are interested you can find out more here:

Schoollog said...

Thanks for writing about Case-Based Learning (CBL), Problem Based Learning (PBL), & Scenario-Based Learning (SBL).
-Schoollog School Management Software