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If you can’t explain something in simple terms, you don’t understand it

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Re: If you can’t explain something in simple terms, you don’t understand it

#121

Post by wnoise »

rocqua wrote: post #82
coldtea wrote: post #46

Earlier quoted context omitted.

It's not just some hard physics that have trouble with the ELI5 / "should be able to explain it" concept. This is also true for literature, poetry, non-analytical philosophy etc. And there the challenges are not about the complexity of the subject, but about its subtlety, and how one needs historical context and/or certain life experiences (or even proclivities) to be able to grasp a particular piece of work.

It's not so much life experiences, but prior knowledge and familiarity. Taking mathematics as the operative example. A lot of deep theorems are trivial when you fully understand all relevant definitions. These proves cannot be stated 'in simple terms' because it took a stack of non-simple definitions to even formulate such a theorem. Explaining the entirety of the stack gets hard when the stack gets deep. For example…

> A lot of deep theorems are trivial when you fully understand all relevant definitions.

A lot of deep theorems comes down to properly choosing the definitions so that the theorems are true.

Re: If you can’t explain something in simple terms, you don’t understand it

#123

Post by dredmorbius »

naikrovek wrote: post #71

This is so untrue. If true, beings that can't speak or write can never understand anything. I understood very early in life that if I cried I would be hit. I couldn't talk, write, or communicate my understanding in any way, but I understood clearly.

Such beings have no social knowledge.

Re: If you can’t explain something in simple terms, you don’t understand it

#124

Post by tgb »

sh87 wrote: post #51
tgb wrote: post #43

Earlier quoted context omitted.

"implies" and "because" are not equivalent. For example, "x is positive implies x^2 is positive" is true but "x is positive because x^2 is positive" is false.

exactly what I was trying to point out. It came out wrong I guess. A statement like "if not a, then not b" is not applicable unless a "implies" b and a "is because of" b. Correct me if I got it all wrong somehow.

"if not a, then not b" is equivalent to "if b then a" and is neither equivalent to nor the opposite of "a implies b". I'm having trouble understanding your point under these confusions. Is it that being able to explain is a sufficient but not a necessary condition for understanding?

Re: If you can’t explain something in simple terms, you don’t understand it

#125

Post by jansho »

jknoepfler wrote: post #68

This strikes me as raw arrogance. Complexity is intrinsic to many systems that are subject of expert study. To tell someone who has devoted their career to understanding a complex topic that they don't understand their subject because they can't express it in layman's terms without doing terrible violence to the underlying phenomenon is ludicrous. This is the sort of thing you'd believe if you were an arrogant 20-som…

A kid just told me "I know Python, I did the games." Facepalm.

Re: If you can’t explain something in simple terms, you don’t understand it

#126

Post by jlg23 »

ivanbakel wrote: post #18
jlg23 wrote: post #12

Earlier quoted context omitted.

> If you rehash it in smaller words, just by information density alone, aren't you guaranteed to be losing some detail? Of course, but when explaining something to another person, one should strive to optimize for being understood, not for the highest information density.

But then what does it mean to be understood? If you skip out the part of the analogy where you actually return to the complex terminology you're simplifying, you haven't produced understanding - you've only made a just-so story which is a reflection of the reality, not a justification for it.

It's the other way around: First was the concept, then the agreement which words we use to describe them.

> If you skip out the part of the analogy where you actually return to the complex terminology you're simplifying, you haven't produced understanding

Billions of people know what a telephone does and how to use one without understanding τῆλε ("tele-", distant) and φωνή ("phone", voice, talk, language). They all get the concept and nobody would argue that they need to understand the terminology as well.

Or: I can teach you to play chess without teaching a single chess-specific term. Yes, other players will laugh at you when you call the pawns "smurfs", but when you understand how to handle your smurf-army, opponents will stop laughing after hearing you announcing "death by smurf-supported horse in 2 turns". (Though they'll definitely hate you for calling a knight a horse ;).

Re: If you can’t explain something in simple terms, you don’t understand it

#127

Post by dtashima »

jshelly wrote: post #115
sh87 wrote: post #86

Earlier quoted context omitted.

Have you ever 'taught' anyone anything? When you do, you'll probably get what Feynman was trying to say. Complexity is intrinsic. Just that as a teacher/guide/explainer, you have to gently guide the novices around enough to invoke a sense of curiosity that will drive the pupil to explore on their own. The task at hand here is to make things less overwhelming, not removing or ignoring complexity. For every complex sys…

I think Feynman's statement is a wee bit over the top, and I will say that being able to teach complex things to novices is definitely an art and certainly one which I do not possess

I think it's partly motivational. There is definitely a level of understanding where it feels like you understand a concept, and then when you try to teach it to someone else, you realize when they ask basic questions that you don't understand it as deeply as you thought you did.

So, if you think you understand something, it's worth trying to explain it simply, so you can push your own understanding of the subject.

Re: If you can’t explain something in simple terms, you don’t understand it

#128

Post by moarrgan »

I feel like a lot of the commenters here are making a false assumption, arguing "just because you can explain something in simple terms doesn't mean you understand it - look how much nuance and complexity gets lost!" That statement makes the assumption that you must explain the subject to another individual to the point where they understand that subject as well as you do. Well, obviously you are going to lose complexity, just on the basis of explaining something in simple terms. The point is that if you cannot distill something to its core ideas to the point where someone else will gain a basic understanding of that concept, then you do not understand what its core ideas are, and therefore do not understand the concept itself. No one is arguing that what took you 10 years and a PhD to understand is something you can explain "simply" to someone and they will emerge with the same level of understanding as you have. No, they will emerge with a basic understanding of that concept if you have explained it well.

Re: If you can’t explain something in simple terms, you don’t understand it

#129

Post by jokoon »

jknoepfler wrote: post #68

This strikes me as raw arrogance. Complexity is intrinsic to many systems that are subject of expert study. To tell someone who has devoted their career to understanding a complex topic that they don't understand their subject because they can't express it in layman's terms without doing terrible violence to the underlying phenomenon is ludicrous. This is the sort of thing you'd believe if you were an arrogant 20-som…

Understanding the fine details is one thing, but unless you can really communicate a synthesis or an analogy, it's impossible to really prove you understand something.

Nobody cares about a genius who understands something until he can really interact about the subject.

Humans work with communication. When you learn about something, you read about it and you process it. To see if you understand it, you must communicate it back. It's not really possible to guess how you brain just learned about something unless you ask that brain to reformulate it.

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