Experts Warn of PBL Pitfalls
No one claims it’s an easy way to teach, but proponents of project-based learning say it is far ahead of other approaches in motivating students and helping them thoroughly learn more of what counts.
But critics and advocates alike warn that enthusiasm for PBL can go too far—producing parodies of effective projects, failing to play to individual teachers’ strengths, and wasting precious class time.
Ben Daley, the chief academic officer of the High Tech High charter school network based in San Diego, is deeply committed to PBL. Still, he lets his new teachers start slow. “I tell them to just do what they know to do really well at first,” he said. “If they go crazy with a big ambitious project and [do] not accomplish much, what good is that?”
Israeli experts friendly to project-based learning suggested on a recent visit to a High Tech High campus that the schools might have become too good at squeezing out classroom talk by teachers. Lecture-style instruction, they argued, can include narratives that stick with students just as well as hands-on experience.
Daniel T. Willingham, a cognitive psychologist at the University of Virginia, in Charlottesville, said the criticism points up a common misunderstanding of constructivism, the well-established theory that learners make knowledge and are not just recipients of it.
“One of the big mistakes people make when they think about constructivism and trying to apply it to the classroom is the idea that learning has to be active, by which is meant physically active,” he said. Rather, it’s mental activity that counts.
E.D. Hirsch Jr., who has written often on the importance of an explicit, well-crafted curriculum, said care is needed to ensure projects are not sidetracked by faith that children will learn good stuff as long as they’re engaged in doing.
“There’s no substitute for watching plants grow,” if you are learning about plants, he said. But, he argued, too many activities turn out to be tangential.
Mr. Hirsch and others say, too, that PBL can present huge “opportunity costs” in the classroom, because other methods can induce understanding in less time. For disadvantaged students, who have fewer opportunities to learn academic content outside of school, that’s a particular problem, according to Mr. Hirsch.
Mr. Willingham said cognitive science so far does not give PBL the decisive edge over other teaching methods that some of its advocates say that it has. Teacher talk and demonstration, cooperative learning, and case studies—all might be effective and, indeed, all could play a role in project-based learning, he said.
“I don’t think any method is obviously superior to any other,” he said. “I’d take any method done well over any method done in a mediocre way.”
Vol. 27, Issue 04, Page 22Published in Print: September 19, 2007, as Experts Warn Of PBL Pitfalls