Regular readers here know of my enthusiasm for PBL: not project based learning, as it is usually refers to, but problem-based learning. Just last week I approvingly quoted Dick Hersh, from his Ed. Leadership article, on the value of problem based learning: “Teaching for such outcomes involves far more than asking students to passively receive information. Consider for example, problem-based or case-study teaching in which students are asked to apply historical, scientific, and cultural knowledge to address real problems.” My own “manifesto,” such as it is, also features placing problems prominently at the front of classroom learning units.
Today, I want to point to a publication from Purdue, the Interdisciplinary Journal of Problem-Based Learning, and more particularly, the current issue’s Introductory piece, Summarizing Findings and Looking Ahead to a New Generation of Problem-Based Learning by Jason Ravitz, Ph.D., of the Buck Institute. (Full disclosure: Jason was a classmate and friend of mine at Harvard, and he kindly solicited my comments on his article before publication, and recognized me in his acknowledgements.)
As an enthusiast for PBL, I am delighted to see the findings in this peer-reviewed journal article report positive outcomes for PBL.
Compared to alternative teaching methods, PBL holds its own on standardized tests of concept knowledge and excels on other kinds of outcomes. Walker and Leary’s meta-analysis combined 201 outcomes reported across 82 different studies. They focused on the average effect size of differences in studies comparing students who received a PBL-based curriculum to those who did not. Althoughsome of the studies they reviewed reported that students in a traditional, non-PBL-based curriculum did better on standardized tests of basic concepts, others did not. Walker and Leary conclude that even on standardized tests of basic concepts “PBL is able to hold its own in comparison to lecture-based approaches” (p. 27).
Moreover, both Walker and Leary and Strobel and van Barneveld determined that when studies use assessments measuring application of knowledge and principles, the results clearly favor PBL….PBL was less effective for short term learning, but they suggest that it was more valuable in promoting other kinds of long term and application-based outcomes.
Jason’s article also points to important next steps in the development of, and research about, PBL. One is that we be sure to consider variants in the way PBL is presented: “One might contrast a “delayed teaching” approach that creates a need for and interest in information before it is presented, to a “pre-teaching” approach in which teachers provide information prior to a problem beginning, or to an approach where students rely on themselves and each other to find information using available technologies.”
Another is that we should avoid false dichotomies between traditional and PBL; sometimes the most effective techniques blend multiple approaches, and though this makes it harder to study and compare the alternatives, we should not close our eyes to the value here.
Finally, I like that Jason recognizes that lecturing and teacher-explaining can still play a valuable role in a PBL classroom. One of my most delightful epiphanies during my good high school project shadowing at 21 schools last year was watching students at New Technology High School, the premier problem-based learning high school in the USA, watching those students pause during the course of tackling a problem to ask their teachers for an impromptu “workshop” or lecture to provide them the information they needed. Jason explains:
The role of content lectures or whole-class discussions within PBL should be considered…Definitions of PBL frequently indicate that teachers in PBL act as facilitators and may “forgo lecturing” about content and focus instead on facilitation strategies and scaffolds for learning….
But students more often may need to be presented with key concepts at critical junctures during problem solving. In these cases, PBL is used to stimulate interest in lectures, to make them relevant and meaningful, not to forgo them entirely (e.g., see Maxwell, Bellisimo, & Mergendoller, 2001). There is a hypothesis that knowledge and skills learning is enhanced by being grounded in an application-level problem, offering better teachable moments and opportunities to learn. When viewed in this way, the distinction between traditional and PBL instruction may really be one of emphasis, leaving room for multiple approaches to be used and studied.
This last is so important. PBL does not have to be a purist, all or nothing approach. Teachers using more traditional lectures and discussions can continue to do so, but seed them with framing problems in order to generate student interest, to connect learning to authentic student concerns, and to clarify to students what the intended learning outcome is of a lecture or discussion.