Ask HN: What do you think makes a good teacher?

The ability to bring out the very best in their student(s) through whatever means. This goes for any mentor, coach, sifu, guru, etc.

The OP sparked a story that Teddy Atlas (boxing trainer for Mike Tyson, Michael Moore, Golden Gloves champ) once told at a book signing.

While training Michael Moore, he had to gain a certain amount of trust / respect from him. One particular instance that stood out in his memory was Michael's fondness of going to the shooting range and firing guns. Teddy never fired a gun in his life but accompanied him to the range.

At the range, Moore and some of his friends shot at the targets and eventually started to egg Teddy on. Teddy finally gave in, took the gun, walked right up to the target, and shot at the bulls-eye at point blank range.

He then turned to Moore and said "THAT's how I fire a gun".

Teddy told the audience he could remember a shift in Moore's behavior and demeanor when he later trained him - looser, more accepting of Atlas's advice. Teddy did what he had to do to bring the better boxer out of Moore.

Moral of the story - go shoot guns with your students :)

Definitely agree, but I've had lecturers who take this too far. My intro. quantum physics professor was a brilliant and accomplished researcher at the bleeding edge of this field whose most basic concepts were deeply mysterious to us students. We appreciated the passion and keep knowledge that informed each of his tangents, but they were pretty impenetrable and very frequently distracted from the material at hand. I left the class thinking he was a brilliant man but fairly poor teacher. Then I had had him the next semester in thermodynamics and he turned out to be great! Certainly he had plenty of knowledge of the field, but he kept the class somewhere within the scope of the syllabus and relayed the foundations to us much more carefully. He focused on teaching, not the material itself.

The GEB lectures you linked are an interesting example in themselves. The early tangents that the teachers launch into on their own are certainly helpful, especially in such a free-form class. But student questions and tangents soon dominate that class too, to the point that I found it quite unbearable. When there is interesting material to be discussed they continually relapse into tired speculations of the "well maybe the universe is just a giant computer simulation" sort. The last lecture in particular is completely dominated, and in my opinion ruined, by questions from the most persistent student. A teacher needs to take charge and keep the class on track. Perhaps in a real class Justin would have.

The objective measure of a teacher's success must be what the class ended up learning regardless of what was or wasn't taught and all other random factors involved.

With that definition in mind, as a former pure math student, the best teaches I had were those who were

- oddly enough, good story tellers! By which I mean, they sounded very much interested in what they were telling me. Their narratives always had at least a few mini-mysteries going on just like in a good story. They used one thing leading to another kind of explanations rather than stating unrelated facts one after the other. The narratives always seemed to have a underlying theme even when that theme was sort of irrelevant to the lesson at hand.

- did not answer my question unless they properly understood what I was asking and why I was asking it. I hate it when I ask X and the teacher answers Y. The good teachers always went to great lengths to understand my questions.

- good mentors and guides and could help your career along if you deserved it. the best ones would go out of the way to make the system reward the deserving.

I think those were the two crucial factors. I have had awesome teachers on all sides of the arrogance, style, humourous, lenience, liberal, demanding, thorough/good enough at the subject matter, popular, good natured/asshole spectra.

Ummm... Not all the good teachers did this, but I very much liked the ones who actually tested what I had learnt rather than whether I was paying attention in the class or taking good notes or pretty much was even present in the class or not.

The best college professors I have had were working professionals who taught on the side or people who otherwise still had some hands-on experience with the subject they were teaching. There's a reason we have the cynical expression "It's academic" as a means to dismiss something as irrelevant to the real world. I generally hate wasting my time on "Ivory Tower"/"It's nice In Theory" type of learning. That stuff not only doesn't prepare you for the real world, it's counterproductive because it's got you thinking stuff that doesn't really work and spending time on stuff that doesn't really work...etc.

Belief that your students can learn to excel, with enough disciplined effort.

Coupled with the ability to convince them of the same thing