This might not apply the constructivism proper. But one thing that bothered me a bit about more progressive methods when I worked as a teacher was how they often became tools of manipulation. By creating the illusion of control and freedom I could get the students to reveal more of themselves, and that gave me more knowledge do use to figure out how to make them submit to the mandated curriculum. This might just be a problem if you are ethically oversensitive. But I prefer facilitating learning in environments where I do not have the power or any reason to force a certain outcome on the learner. And in those situations constructivism can be quite useful, as can drills.
I've been thinking about this for a while. I spent the last 10 years teaching music lessons to children and a few adults. I haven't studied education formally, but have read some of the literature that I thought would be helpful.
My feeling at this point is that constructivism is a useful thing to do, but that it takes a lot of investment on the part of the teacher to pull off at all. It also is slower than the "imitative" approach to education. It is obvious to me that it would overall harm, not help, a person to win a Nobel prize in physics by requiring them to reconstruct all of physics on their own first. But mixing in experiences of figuring out chunks of knowledge for oneself is more satisfying and useful than pure imitation.
Teaching still relies a lot on the teacher's intuition and personal relationship with the student. It's not enough to implement constructivism. To use it effectively, you need to implement it well, and on the correct problem area. Insufficient constructivism is not the cause of all learning challenges or experiences of student boredom. Figuring out the right blend is just one of several major problems in the overall challenge of optimizing a student's education.
So to refine your original post, I recommend shifting more toward questions like:
When is constructivism the right approach for a particular student or subject, and why?
What proportion of constructivism vs. imitative approaches is ideal?
Can we know when constructivism is the key issue for a particular educational problem?
If one student is taught addition via constructivism, and the other by imitation, is there really a fundamental difference in their understanding of addition? Or is the difference in the amount of skill they gain in two different approaches to learning how to learn, rather than in the amount of skill they gain in the object-level topic?
How can we implement constructivist approaches for new topics where it's not normally applied?
In encouraging people to make models that fit their particular psychology me make them use models that are rare or seldom threaded. This might give them illusory sense of uniqueness, they might not benefit or expect to benefit from the knowledge of others.
Coming up with their own models they might have unique problems that if we encourage to take their own constructions seriously they will have problems that we don't have answers to. A geology teacher teaching that earth is round in some capacity needs to be able to deal with flat-earther talking-pint and fumble points. taking a positivde spin on this is "they make their own reserach questions" but making a bad spin is "we spend more time of doing it wrong in X ways rather than the known working ways"
The motivation for the question is to help a (constructivist) teacher do their job well, or to help a teacher unfamiliar with constructivism learn to do their job better.
This assumes that educational paradigms matter a great deal. I would expect that skill around effectively projecting authority in front of children and classroom management are more important for the teacher to do their job well.
I'm sure constructivism works for some people some of the time but for a public mass education system it doesn't seem scalable. One of my goto bloggers on education has written a lot against this idea, this is one of his posts. https://gregashman.wordpress.com/2020/05/23/whatever-happened-to-constructivism/comment-page-1/
In writing fiction, advice often given to new writers is "show, don't tell."
I've long thought that this advice is overly simplistic, or possibly incomplete. In the end, everything a writer writes is telling something.
"Mark was sad." - Telling Mark's emotion
"A tear fell down Mark's cheek." Showing Mark's emotion, by telling what's going on.
Without giving the matter an abundance of thought, Constructivism seems similar to me. Everything a teacher teaches is some kind of password. And even when the teacher is trying to get the student to construct mental models for themselves, the teacher is telling something.
So the question isn't whether or not constructivism is superior to memorization, any more than showing is superior to telling in writing. Both are necessary; the question is at what level of abstraction each is best used.
My personal opinion is that routine skills - the kind of thing you have to do all the time, over and over again, like hammering a nail in carpentry or adding two number together in math - should be memorized, at least at first. Not because that's inherently superior in any sense, but because it enables other, more complicated tasks to proceed faster. Those more complicated tasks are then good candidates for constructivism.
Another way to say this is that gears are made of atoms. Since education has to start somewhere, might as well start by memorizing gears so they can be constructed into complex machinery.
Then, later, you can go back and explain that gears are not the fundamental unit of matter, or ten is not a fundamental base, or nails aren't the only way to secure two pieces of wood together.
Seems to me that constructivist education is already "in the water supply" of Less Wrong. My tweet-length definition of constructivism would be "teaching students so that they construct mental gears-level models of the subject, as opposed to just memorizing the teachers' passwords"; and I assume most people here would agree that this is the right thing to do.
My question is how much this is a fair characterization - or perhaps it is abstracting away some very important stuff - and what are the best arguments against constructivism. Because, per Litany of Tarski, if constructivism is wrong, I want to believe it is wrong; although frankly I do not expect it to be fundamentally wrong, more like constructivists having some typical blind spots, in which case I want to know where they are.
The motivation for the question is to help a (constructivist) teacher do their job well, or to help a teacher unfamiliar with constructivism learn to do their job better. Therefore if the objection is e.g. that Piaget was historically wrong about some technical detail, the importance of this objection depends on how likely today someone is to make a mistake in designing their lessons because of that fact.
Here are my attempts to steelman the opposition to constructivism: