Those Who Can Do, Can’t Teach

You can see this phenomenon in American football where the pretty good quarterbacks often become great coaches but the very best quarterbacks rarely do. The pretty good ones got good by being very detailed students of the game, memorizing thousands of plays and watching as much game film as possible... the absolute elites like Joe Montana often just had the ability to see an open receiver 30 yards away and throw the ball with 4 inch accuracy to the point that he would have run to during the ball’s flight.

I don't think this is always true.

Some of the best books and courses I've taken were from people who are experts at what they do. The keyword there is "are", not "were".

There's just an extra level of insight you can get from someone who is in the trenches doing real work, rather than trying to learn from someone who never really did the thing for real but happens to be an "armchair expert".

I think this is especially true for software development material and it's one of the reasons why I continue to do freelance work while creating video courses on the side. If I stopped consulting then I would become rusty in my craft if all I did was come up with course material.

An example of this would be DHH's books. Would you rather learn business from DHH (someone involved in a ridiculously successful business that operates today), or a college professor who likely never ran a really successful business but knows a ton of theory about it but also has 30 years of teaching experience?

I would argue DHH's advice in his books would be more valuable, even if he happens to be a less skilled teacher on paper.

Teaching like any learned skill requires significant commitment and practice. Those who "do" like Einstein aren't prepared to carve out 1000s of hours from their scientific research, where their passion lies, to learn and practice how to teach well. I'm quite sure that if Einstein loved teaching as much as research he would learn to be an outstanding teacher.

The notion that there's a "do <-> teach" continuum is just silly. OK, Einstein was great at "do" and lousy at "teach". How about Feynmann?

It is also hard to formalize and convey to someone else what one already knows: https://en.wikipedia.org/wiki/Tacit_knowledge

If it is indeed true, then Feynman is probably the biggest exception to it.

This topic is plenty debatable.

Many people I meet who are excellent at their jobs are lousy teachers. They tend to have instinctive grasp of things which doesn't transition well in teaching.

But people who are good but not great at their jobs tend to be the best teachers. One of the reason is that these guys tend to have detailed notes and learned through experience.

As the article mentioned Einstein as a teacher, I think it’s worth asking about his writing too. I think his actual papers are very good at explaining the theory and indeed better than many textbooks. I think a good way to start learning eg special relativity is to get a copy (available online) of Einstein’s first paper on special relativity and read it. The paper has to explain it for people who have never really seen such a thing before. Obviously a certain level of mathematical ability is required to understand the paper and maybe this is more than required by a modern textbook. A modern textbook may also explain things in a different way with eg 4-vectors and lots of spacetime diagrams.

Suppose that there are 1% of people in a field who are considered great at doing and 2% who are great at teaching, then just from expectation without additional knowledge the vast majority of great teachers won't be great at doing.

Also, if the percentage of people who are great at both is higher than 0.02% but lower than 1%, there is a positive correlation between teaching and doing, but it is not a perfect correlation. I suspect this is the case.

Why? Both doing and teaching something well often require clear and systematic thinking. However, there are also disparate skills required for each and only those with time, inclinations, and opportunities to practice both skill sets could become great at both.

I faced the consequences of this first hand. In the Abstract Algebra class we were recommended a very standard book by one of the giants in the field and I suffered the entire semester depending on that one book. I should have switched a little too early. I learnt it the hard way and advise anybody to look for alternative resources or more explanations once you start seeing a lot of text such as "and the rest is left as an exercise for the reader" without much explanation irrespective of the field you are in and regardless of the big name attached to a source. At times an obscure blog is able to explain a difficult concept much more easily.

Now that I think about it, the worst CS teachers I've had were the ones who taught part-time while working in respected positions in industry, or had a strong industry resume behind them.

Previously I had wondered why some of my best CS professors in university didn't go for a private sector job where they could be earning 1.5-2x doing programming instead of teaching it, but now I realize they would've been mediocre programmers instead of great teachers.

Nonsense. All the great teachers I had were also great practioners. I like to see myself also there. Rhetoric is trainable.

The irony that he cites Harvard Physics is the vanguard of rethinking how to teach Physics, and possibly the root of this article come from Harvard Physicist Eric Mazur: https://www.youtube.com/watch?v=LIFL0K184kg

They say the best teachers struggled with the subject.

Does this work the other way around?

People tell me I'm an excellent teacher, but I'd consider myself a mediocre developer...

> My renowned astrophysics professor taught us how the universe seemed to be expanding, but never bothered to explain what it was expanding into (still waiting for someone to demystify that one).

Wow... and this person went to Harvard??