I seem to have had the same argument with a number of people so it’s probably worth putting my response in a short post.
Following my criticism of Project Based Learning, some have suggested that I lack an understanding of how it is conducted these days. There is actually a lot of explicit instruction involved (and formative assessment). We can therefore use the evidence base for explicit instruction (or formative assessment) and repurpose it as evidence for Project Based Learning.
This is an interesting argument and one that I observe a lot in education, sometimes less overtly stated than this. You see it, for instance, when people claim that Reading Recovery now makes some use of phonics.
The obvious answer is: get your own evidence. If PBL is the question then we need evidence for PBL, not for a strategy that might or might not be used as part of it. After all, PBL has been around for at least 100 years so the evidence should be available by now.
However, if we take this argument at face value there are two major problems.
What would a fully guided project look like?
In a fully guided project, the teacher would set the objective and control all of the methods that are used to reach that objective. I have some experience of this running class practicals as a science teacher.
Imagine a practical to find out which foods contain starch. I might lay the foods out, the iodine and the sample trays. I would probably explain each of the steps and also give students a ‘recipe’ card with all of the steps written down.
It’s worth mentioning something else about this experiment: I conducted it with a class as part of some research work carried out by the Institute of Education whilst I was training. The object of this was to try to get students to think about the science while conducting the practical work.
Even with such a simple design, this was extraordinarily hard to do. My students’ heads were in the space of equipment and instructions. It was really difficult to get them thinking about the nature of the foodstuffs and whether they should contain starch.
This illustrates my point that activity does not necessarily imply learning. At the end of the experiment, many students could not even recall which foods contained the starch.
Projects imply students finding things out for themselves
In reality, of course, nobody would describe such a fully guided activity as a ‘project’. The word implies student choice and an element of finding things out for themselves. So it is clear that, in essence, projects are not a form of explicit instruction.
Of course, you can mitigate the lack of learning that takes place during project work by bookending it with explicit instruction. This is something that many generations of science teachers have learnt to do with practical work. But this does not make an argument for projects.
So why do projects at all? Again, I will point out that they can be effective when students have already learnt all of the required knowledge and skills. There is also an argument for variety.
As a science teacher, I would still conduct practical work despite its limitations. This is because practical work is something that sets science apart and some students enjoy it. I would never argue that it is more effective, leads to deeper learning or that science teaching should be ‘based’ in practical work.
These are the arguments that are made for PBL and that lack evidence.