Things you know too well to teach?

I had just this situation when my daughter was in 7th grade. She had a homework problem she couldn’t figure out. I went through the equations, set it equal to zero, and then I said, and now, you just solve the quadratic and you’re done.

She looked at me like I’d grown an auxiliary head. “Solve the quadratic? What’s that?”. Says I, you have to know how to solve the quadratic, this problem is unsolvable without that, you’ve got too many unknowns. You must have forgotten it, or been absent or something, this solution isn’t possible without that ability.

I went to school with her to find out what was wrong because she’d clearly missed something. It turns out she was expected to guess. She was supposed to try a number, go “nope, too small”, try another number, “nope, too big” and gradually work her way to an acceptable solution. I’m not even close to an expert, but I can’t teach math to a 7th grader.

I know FileMaker quite well and can teach it pretty clearly as well; knowing it solidly and thinking in its terms doesn’t keep me from being able to describe it to people who’ve never worked in it.

Then there’s hearing chords and intervals in music. I can’t teach that. I can’t understand how anyone can NOT just hear it. It’s like trying to teach someone how to distinguish blue from red. The way you know that the violin has the minor third while the french horn holds the fifth and the clarinet is coming down a chromatic scale ending a major 2nd above the root is that you listen adn when you listen you hear that the violin has the minor third while the french horn holds the fifth and the clarinet is coming down a chromatic scale ending a major 2nd above the root.

For every example provided by someone of not being able to teach something they know really well, is just an example of someone not knowing how to teach. I can provide numerous examples of different people that teach things very well…they are good teachers.

Thread title should be changed to "Some people know how to teach and some people don’t".

I know HTML really well but I’m not sure I could teach it. I’ve only ever learned it on my own, so I don’t know how things should be explained or even why things work or best practices. I never learned any of that myself.

But it is possible to know how to teach some things but not others.

Of course, yes, but these two skills are not mutually exclusive. The premise of the OP is that if you know something so intimately you may not be able to teach it, for which there is no proof, other than examples of people that are likely bad teachers.

Well that’s insulting considering I gave an example of the types of things that were very hard for me to teach because I knew them so well since I wasn’t sure how I learned them myself (came to me very easily). It took time and effort to learn how to teach them well, but because I am a good teacher I put in the effort. But when I was new, there were definitely things I could teach well immediately, and subjects I had to figure out how to teach well for the person who found the material was challenging.

Richard Feynman is the perfect example of the orthogonality between expert knowledge and ability to teach.

I would hope nobody claims he’s not an expert. And he was renowned for his ability to explain physics concepts to just about anybody.

That’s not due to your expertise, though. You don’t find it hard to teach because you’re an expert, but because you aren’t sure how to teach that particular topic(s) to another person.

Teaching is an expertise of its own, and knowledge of a subject is just one aspect of many to developing teaching expertise. That’s not a knock on your level of knowledge or general ability to teach but on your ability to teach a particular topic.

I don’t think “orthogonality” is the right word, since someone without any knowledge isn’t likely to be a good teacher. Rather, knowledge (at least at a competent, if not expert, level) is a necessary but not a sufficient condition for being able to teach a subject well.

However, having a subject come naturally to you is not a necessary condition, and arguably (as some here have claimed) it may even be an obstacle.

I agree but to a point- there are definitely topics I am so well versed in and have such specialized depth of knowledge that it gets in the way of being an effective teacher. Part of teaching is stepping back and figuring what is relevant, what is not, which parts to simplify etc. Having that depth of knowledge can make teaching (as in organizing the class, developing the curriculum as well as the act if presenting the material) a real challenge.

The good teachers have the skills to figure it out. I’ve been teaching at the college level for a long time and am in a position to have evaluated many, many professors. For some people, who are otherwise excellent teachers, I’ve seen their expertise be a roadblock to be overcome in order to be effective.

I don’t see it as an insult. Rather, teaching is a skill, just like any other skill. You originally found an area difficult to teach, but you put effort into it, and now you can teach it. That’s an excellent example of how teaching a subject is a separate issue from knowing the subject.

You, as a good and determined teacher, saw that you had to work at learning how to teach part of your subject area - and now you can. That shows: (a) you are a good prof, the kind I would want to have; and (b) that it was not the case that your expertise made it impossible to teach the subject matter - because you have learnt how to do it.

Thanks. But his claim was that it wasn’t the expertise that was the problem, just being a bad teacher. I was a strong teacher in many other areas at that point, so the characterization was unfair. I was able to overcome this particular problem because I was a good teacher already.

The reason I struggled was because I had too much expertise in this area and struggled with teaching something I learned intuitively, not because I was poor teacher.

This happens to me all the time. Someone will ask a question in class, and I’ll think it an excellent, insightful question and try to give an explanation with detail, but (usually barely) within the level of the class material. The student will then say, "What I really wanted to know was ______ <== something most often quite basic.

Once a few homework assignments or test have been done, you get to know at what level a particular student’s questions are likely to be. Often the smart student’s questions are then answered after class.