So there's an argument for going into the classroom (as a teacher) completely unprepared, stumble through the material, reason things out in fron of the students, go down hopeless calculations for a while, then say "scratch that", "let's see....hmmmmm", etc....Nothing should be clear, the students would have to make huge efforts just to find out what's on the hw. I know some people like this (not by design). I wonder if their students learn some important life-skills though.

I sort of unintentionally had this happen to me. When I was 13 I moved to a new school which was a little less competent than my previous school. In my previous school all the information was packaged and delivered to us to memorize. In this new school the teachers would just roughly go over the topic and it required a lot of independent effort on my part to understand the subject matter.

This led to this mini explosion of clarity in my head. While in my previous school I was bored of learning and depended almost exclusively on rote memorization, this new s... (read more)

14gjayb9yIn my own experience, this can work well in a small group with engaged students. I had an excellent optics class where we would try to derive a known result as a group: the professor would explain the experiment, draw a picture, and then ask us to help. If we got him going, he would take a few steps, then ask again. Now, I remember next to nothing of equations for optics, but I have a very good idea of how to go about figuring out the outcomes for various experiments theoretically. On the other hand, I've had professors stop referring to notes partway through a derivation or proof, get dreadfully confused, and simply frustrate themselves and their students. So this may be an all-or-nothing: for a given day or proof or class, either do a group derivation or present the material on a platter. I will say that I also had a high school English teacher who would use the wrong word or give a ridiculous interpretation in the hopes that a student would correct him and learn to not always trust authority. I liked the theory, but in practice it meant that the attentive students had to do work that was frequently repetitive and irritating, such as correcting word choice or grammar (as these were students who were already thinking) while those who could learn most from such a lesson never noticed it.

Two More Things to Unlearn from School

by Eliezer Yudkowsky 2 min read12th Jul 2007155 comments

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In Three Things to Unlearn from School, Ben Casnocha cites Bill Bullard's list of three bad habits of thought: Attaching importance to personal opinions, solving given problems, and earning the approval of others. Bullard's proposed alternatives don't look very good to me, but Bullard has surely identified some important problems.

I can think of other school-inculcated bad habits of thought, too many to list, but I'll name two of my least favorite.

I suspect the most dangerous habit of thought taught in schools is that even if you don't really understand something, you should parrot it back anyway. One of the most fundamental life skills is realizing when you are confused, and school actively destroys this ability - teaches students that they "understand" when they can successfully answer questions on an exam, which is very very very far from absorbing the knowledge and making it a part of you. Students learn the habit that eating consists of putting food into mouth; the exams can't test for chewing or swallowing, and so they starve.

Much of this problem may come from needing to take three 4-credit courses per quarter, with a textbook chapter plus homework to be done every week - the courses are timed for frantic memorization, it's not possible to deeply chew over and leisurely digest knowledge in the same period. College students aren't allowed to be confused; if they started saying, "Wait, do I really understand this? Maybe I'd better spend a few days looking up related papers, or consult another textbook," they'd fail all the courses they took that quarter. A month later they would understand the material far better and remember it much longer - but one month after finals is too late; it counts for nothing in the lunatic university utility function.

Many students who have gone through this process no longer even realize when something confuses them, or notice gaps in their understanding. They have been trained out of pausing to think.

I recall reading, though I can't remember where, that physicists in some country were more likely to become extreme religious fanatics. This confused me, until the author suggested that physics students are presented with a received truth that is actually correct, from which they learn the habit of trusting authority.

It may be dangerous to present people with a giant mass of authoritative knowledge, especially if it is actually true. It may damage their skepticism.

So what could you do? Teach students the history of physics, how each idea was replaced in turn by a new correct one? "Here's the old idea, here's the new idea, here's the experiment - the new idea wins!" Repeat this lesson ten times and what is the habit of thought learned? "New ideas always win; every new idea in physics turns out to be correct." You still haven't taught any critical thinking, because you only showed them history as seen with perfect hindsight. You've taught them the habit that distinguishing true ideas from false ones is perfectly clear-cut and straightforward, so if a shiny new idea has anything to recommend it, it's probably true.

Maybe it would be possible to teach the history of physics from a historically realistic point of view, without benefit of hindsight: show students the different alternatives that were considered historically plausible, re-enact the historical disagreements and debates.

Maybe you could avoid handing students knowledge on a silver platter: show students different versions of physics equations that looked plausible, and ask them to figure out which was the correct one, or invent experiments that would distinguish between alternatives. This wouldn't be as challenging as needing to notice anomalies without hints and invent alternatives from scratch, but it would be a vast improvement over memorizing a received authority.

Then, perhaps, you could teach the habit of thought: "The ideas of received authority are often imperfect but it takes a great effort to find a new idea that is better. Most possible changes are for the worse, even though every improvement is necessarily a change."

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