As one paper put it, there is a “paucity of robust research” on project-based learning. Yet in the ed-school world and in many journals and professional organizations, it’s often touted as a pedagogical gold standard. This is traced back to John Dewey and William Kilpatrick and is contrasted with so-called traditionalist “fact cramming” and “assembly line” methods. An earnest goal of many professors and organizations, then, is to perform the first studies that secure evidence of its efficacy. Who can find the first picture of Sasquatch?
One study published earlier this year purports to have done so, i.e., proven that project-based learning is as effective as its proponents claim. The publication Edutopia celebrated it as “compelling evidence.” The researchers implemented intensive project-based learning programs in AP U.S. History and AP Environmental Science classrooms. The history class featured “student debates over historical and contemporary constitutional issues, mock presidential elections, and, for the culminating project, creating a political action plan intended to move an agenda item (e.g., immigration policy) through the political system.” The science classroom functioned similarly, building itself around projects as the primary means to cover the curriculum.
It was surely engaging and, in the end, students in the PBL classrooms scored 8 percentage points higher than the control group on their AP exams. At first glance, it seems convincing. Under further scrutiny, however, the research is questionable; the picture is fuzzy.
There’s an essential question in such randomized controlled trials: “Compared to what?” In this case, the treatment group in the project-based classrooms received “curriculum, instructional materials, and robust professional development supports for teachers.” They compared this group to a control group of classrooms doing “business as usual.”
Call me crazy, but I’d imagine any class that received robust professional development and instructional materials designed and tested by researchers might see improvements pretty much regardless of the instructional approach in question. If I spent extra time reflecting on my practice and conferencing with local professors, my teaching would probably improve—regardless of whether it was PBL or direct instruction. There are simply too many variables for this study to prove much of anything.
And that’s without even getting to the difficulty of defining what exactly project-based learning is. Like a Rorschach test, the phrase signals quite different things to different users, so gauging its efficacy is all the harder. Even the most prominent adherents of teacher-led instructional practices still incorporate projects of some kind, even if they are not the basic classroom structure.
This study would be inconsequential if it existed in isolation. Much more concerning is other research that finds that PBL actually risks learning loss. A similar study implemented a project-based approach in eight different classrooms. To the researcher’s dismay, the results went in the opposite direction:
- Adopting PBL had no clear impact on either literacy (as measured by the Progress in English assessment) or student engagement with school and learning.
- The impact evaluation indicated that PBL may have had a negative impact on the literacy attainment of pupils entitled to free school meals.
The authors of this second study themselves admit that “the existing international evidence on the effectiveness of PBL is relatively weak.” Reviews of the literature confirm this conclusion. One seminal paper led by Paul Kirschner, professor of education at The Open University, says that any minimally guided instruction like PBL “is less effective and less efficient than instructional approaches that place a strong emphasis on guidance of the student learning process.”
Kirschner attempts to explain why PBL falters in its application. In short, it ignores “the structures that constitute human cognitive architecture.” In simpler language, there’s a vast base of research into how the human brain learns. While we learn elementary skills like verbal language through play and experimentation, more complex topics and skills—ancient history, scientific concepts, written language, the stuff of culture—require explicit instruction and practice.
We cannot experiment our way into memorizing the multiplication tables. Learning the nature of the solar system requires clear explanations, examples, and analogies. Writing necessitates models and practice.
What’s more, projects can be wildly inefficient. Time spent distracted, dealing with the project itself, figuring out software, and suchlike is less time for covering models, receiving direct instruction, practicing, and other productive uses of class time. Barak Rosenshine wrote an excellent summary of the most effective strategies for teachers to use, things like questions, modeling, and structured practice. Any time spent cutting and gluing a diorama means less time for these.
To be clear, none of this research is an irrefutable repudiation of PBL. There are countless anecdotes of PBL models working. High Tech High, a successful charter network in California, is full of such examples. However, anecdotes are only that.
Project-based learning might work. Sasquatch might also exist. Even so, the evidence available today suggests that PBL doesn’t deserve its place on the pedestal, and that I can camp in the woods without worry.
