(cross-posted from my blog, Sunday Stopwatch)

"But when am I going to use any of this?" - every single kid in school ever.

There's an idea that project-based learning is more efficient than the traditional school curriculum. It makes sense, but so did the idea that learning styles are important, and that turned out to be false.

Here are a couple of thoughts before I delve into the research:

  1. When I'm learning about something, it stands to reason that, in the long run, I'll learn more if I'm interested in the material. One way of being interested in the material is to have a specific goal in mind, the achievement of which depends on you learning the material. However, as anyone with any goal whatsoever knows, some things you want to do very much, but you really don't want to do some of the background work for them.
  2. Having a specific goal (a project) will serve as a wrapper around the exact same thing you would be doing following a traditional curriculum: reading textbooks and solving quizzes. Let's say you're trying to build a robot and realize that you need to learn about classical mechanics to achieve that goal. You'll bust out the textbook, try to figure out the page which will solve your specific problem, you will fail because you have a specific situation which requires a deeper understanding of the entire field of classical mechanics, and then you'll end up doing what you would have been doing anyway: reading textbooks and doing quizzes.
  3. With that being said, you do provide an answer to the question "why do I need to know this?", but it's not clear to me that knowing an application for something really makes a difference in knowledge retention. I know the application of the equations used for electrical circuits, but it doesn't mean I remember them.
  4. But maybe the act of applying itself is what makes the knowledge stick in the mind. There's a relatively easy way to test this: set up three groups, two project-based, and one traditional. When one project-based group gets stuck on the project, and they obtain the knowledge needed to "unlock" progress, simply level them up without them actually applying the knowledge. So if they're e.g. building a robot arm, and they are missing some crucial insight into a particular subfield of physics, when they go and obtain that knowledge using traditional methods, just give them a working robot arm (or whatever the project is) and face them with the next challenge. The other project-based group should actually apply the knowledge - the members themselves should go and build whatever they're building. Finally, test the knowledge of the three groups and see if the act of applying knowledge had any effect on retention.

I expect that having a project-based approach serves as a minor boost to motivation, but doesn't really make a difference regarding knowledge retention.

So, what does the research say?

This systematic review says that it's inconclusive because the studies weren't done well. And this is only for small kids. I could imagine that different approaches might have different effects depending on age.

This paper describes how biomedical engineers collaborated on some projects and concludes that project-based learning works well. Direct quote: "It is felt that the projects were successful to some extent. They certainly achieved several important learning outcomes of teamwork, ability to apply theoretical principles from multiple disciplines, effective communications, creative problem solving, and awareness of the importance of globalization especially in the biomedical engineering field." It is felt that I don't have any new insight after reading the article.

This paper tries to figure out the effects of project-based learning on "on collaborative learning, disciplinary subject learning, iterative learning, and authentic learning", none of which sound like "we made both the control and experimental group take the same quiz afterwards". And looking at the methodology - it's not. They just asked a bunch of teachers some questions. I don't consider this informative.

There's "Baran, M., & Maskan, A. (2011). The effect of project-based learning on pre-service physics teachers electrostatic achievements. Cypriot Journal of Educational Sciences5(4), 243-257.", but I can't access that text, only the cached abstract, which speaks in favor of project-based learning. But they had only 20 people in the treatment group, and I have no idea what the methodology even was, so... this one also fails.

This review also concludes that "a causal link between PBL instruction and positive student outcomes cannot be established with certainty".

My conclusion: we just don't know for sure. I think that having a project serves as a motivator and a framework, but if you are the type of person that doesn't need to immediately know how you'll apply the thing you're learning, then it's more or less the same. For example, if you blindly trust that logarithms will be useful for something later on, then you don't actually need a project for which logarithms would prove crucial. In both cases, you'll end up doing the same thing: reading textbooks and doing practice problems.

Please let me know if you know more about this topic!

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4 comments, sorted by Click to highlight new comments since: Today at 7:39 AM

I find that it is complementary. If I spend a lot of time reading about a subject, I can build up a great base of knowledge, but if I then later do projects involving that subject, I tend to find out that a lot of my priorities were upside down, and tend to see a lot of limitations and conditions that are hard to pick up from reading.

On the other hand, if I spend a lot of time practicing without any theory to guide me, then I find that I make some progress, but often when I later learn theory, I see huge blind spots and mistakes in my work, as well as huge shortcuts and lots of tricks that I should've applied.

I would also bet it depends heavily on how you measure it. Pure book learning probably boosts pure book scores more, while pure practice learning probably boosts practical task performance more (at first at least, until you've calibrated the book knowledge to the real world).

What a coincidence - I was just writing about this topic myself!

I think the challenge is partly that project-based learning (PBL) is under-defined and contextual, partly that it's time/money/energy/creativity-intensive, and partly that it's dependent on a pre-existing level of competence, passion and interest in the particular PBL topic.

One way of framing it is that a person has a rich, multifaceted goal:

  • To build specific projects that matter to them
    • Example: building particular pieces of lab equipment that they need for an experiment
  • To become proficient at the synthetic and physical skills
    • Example: the physical and mental intuitions useful for putting together electronics, mechanical parts, and chemical reactions
  • To have sufficient analytical proficiency to diagnose problems and be efficient in their design
    • Example: the formal and informal theory and reasoning skills

If a person like this also is willing and able to throw a significant amount of their time and money at PBL, I think that they'll tend to see stellar results compared to the traditional trod through a textbook with occasional labs.

I'd be very curious to know if there was any successful research into predicting whether or not a particular PBL effort would succeed or fail. It seems like the same approach that's been used to evaluate the plausibility of social psychology research might be useful here. Give people a series of descriptions of PBL experiments, and ask them to predict whether or not the experiment would or would not reach significance or have a given effect size. I'd bet that people would be good at making such predictions.

Followup: I scanned the first listed paper from the systematic review. I think the challenge to arranging the prediction tournament I proposed above would be in producing descriptions of the studies.

Consider the review's approach to finding studies for inclusion.

PjBL and PBL are usually described as active, student-centred methods of instruction that encourage students to work in collaborative groups on real-world questions or challenges to promote the acquisition of higher-order thinking skills, while teachers act as facilitators of learning...

On January 23th 2020 the first author (MF) performed an electronic search on the Web of Science, PsycInfo, and ERIC entering the terms “(project based OR problem based) AND (learning OR intervention OR approach OR instruction)” into the Topic field...

The studies were only included if they met the following criteria: c1) the aim was to evaluate the effect of PjBL on content knowledge; c2) they followed a pre-post design with control group; c3) the target sample comprised students from kindergarten to grade 6; c4) they were written in English; and c5) they were peer-reviewed.

To avoid being excluded on the grounds of topic irrelevance, a study only needed to:

  • Use the terms "project based" or "problem based" as well as one of the terms "learning," "intervention," "approach," or "instruction" in the topic field.
  • Strike the reviewers as attempting to "evaluate the effect of PjBL on content knowledge," presumably by fitting the definition they give in the second paragraph of their introduction.

Note in particular that, by the definition they give, only some amount or form of encouraging and facilitating of any type of collaborative, "real-world" "questions or challenges" is required to fit their definition of PjBL. This is an extremely expansive definition.

You yourself note that the most obvious reason this review finds mixed results is that, in your words, "the studies weren't very well done." I think this is correct, but we also can chalk up the problem to:

  • The reviewers, for having such an open-ended definition of PjBL (perhaps by necessity if there aren't many studies available)
  • The field itself, for the same definitional inadequacies when it's in their power to try and do better when designing their studies.
  • Probably extreme resource constraints in designing and executing PjBL experiments.