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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

#151

Post by dec0dedab0de »

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…

I think your examples prove the opposite, that if you can explain something in simple terms than you do not necessarily understand it.

I do agree that poor communication skills are not a lack of understanding, however, not being able to explain something I thought I understood is a personal redflag.

from the zen of python:

If the implementation is hard to explain, it's a bad idea.

If the implementation is easy to explain, it may be a good idea.

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

#152

Post by tgflynn »

SomeStupidPoint wrote: post #137
jokoon wrote: post #129

Earlier quoted context omitted.

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 communicat…

I care that the people at CERN can make a working LHC, not that they can communicate it to me succinctly (eg, in under 2 hours). It's fine that it takes 150-300 hours of back-and-forth communication to transfer the ideas behind how it actually works. That seems like a reasonable amount of time to communicate a complex idea to a novice. There's also layers of understanding: The LHC bangs two rocks together hard to see…

"The LHC use magnets to accelerate protons" - That statement would really confuse someone with a basic knowledge of physics because static magnetic fields can't do work and hence can't accelerate particles.

The acceleration is actually done by electric fields produced in RF cavities.

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

#153

Post by cestith »

Animats wrote: post #75

That works for physics, which seems to be parsimonious with its base concepts. The equations which define most of physics fit on one sheet of paper. It doesn't work for biology, which is complicated at the bottom. Evolution doesn't have the parsimony of physics. Nor does it have to be understandable by humans. Whether it works for software is a design issue. It's certainly possible to create software which cannot be…

"There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult." - C.A.R. Hoare

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

#154

Post by ChuckMcM »

"What I cannot create, I do not understand."

This actually came up for me at the office. I was asking a bunch of questions about the Z transform and the Fast Fourier Transform. The person I was talking to said, "Hey, just call the function in MATLAB, it doesn't matter how it works, just that you understand what it is saying."

All of my life I have rebelled at this notion. My earliest recollection of running into it was when I was in grade school and took apart three wind up alarm clocks, each more carefully than the one previously. My Mom was curious what I was looking for and I told her, "How does a clock know how long one second is?" She didn't know, and I didn't know, and while I had mastered using a clock and accepting that it would go off when I set it to go off, I didn't really "know" how a clock worked until I had taken apart and identified, (and modified to validate the identification :), the escapement.

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

#155

Post by frahs »

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…

As an arrogant 20-something year old, I disagree :P.

An important distinction to make here is whether you're teaching someone to intuitively reason about something or to logically calculate it precisely.

I think as long as someone grasps the basics of high school math and has a decent working memory, they should be able to learn how to calculate anything precisely given that you break it down into simple steps. If you don't know how to do that, you have no clue what you're doing.

Then there's intuitive reasoning. I think for most things, if you're familiar with a topic, you should be able to teach it in a way that makes sense. Of course there's exceptions -- some people are incredibly brilliant, but lack social awareness. I think that's the exception rather than the average case.

But not all topics are so easily reduced. There's probably some exceptions. The strongest that comes to mind is quantum computing. As many times as you can explain things like superdense coding, there's still a sense of "magic". Where the results of the math seem unnatural. And you go back through each step and try to figure out where things went weird. But each step is a logical progression from the beginning.

On that note, Michael Nielson's "Quantum Computing for the Determined" is one of the most well-taught courses I've found, and does a very good job of stepping the viewer through a very complicated topic. Michael Nielson clearly knows what he's doing :)

http://michaelnielsen.org/blog/quantum-computing-for-the-det...

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

#157

Post by jpmattia »

If curious: This Feynman quote was more specifically about the spin-statistics theorem.

https://en.wikipedia.org/wiki/Spin%E2%80%93statistics_theore...

And to be fair, it's pretty rough sledding even when you understand the operators involved.

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

#158

Post by munificent »

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…

    > 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.
The article doesn't say you should be able to explain it to a layperson, but to a beginning student. This is a distinction that matters. A beginning student in your field should have enough preparation that what you need to explain is only the parts that relate to your particular area of expertise.

No one should devote their career to simply understanding a topic. If all you do is load someone else's work into your head, what value you are adding? A career is a mixture of learning as well as exploring and discovering new things. Explaining just the parts that are known is a much smaller order than transmitting the effort of your entire career into words.

Note also that Feynman isn't claiming you should be doing this all the time, but that you should be able to. I've been programming for about two decades and I've learned a ton (and yet still have even more left to learn). I'd like to believe that, yes, I could explain almost all of it to a beginning CS student or even a lay person.

They might not have the patience for me to build up all of the necessary structure from one simple piece at a time, but I think I could. After, that's how it got into my head in the first place. The parts that I couldn't do a good job decomposing and walking through are exactly the parts that I probably don't have a good handle on. (For me, networking and operating systems come to mind. I know some of the jargon, but I don't really know how it all works.)

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

#159

Post by jlg23 »

BurningFrog wrote: post #70
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.

This discussion really needs a concrete example.

A classical joke from the GDR (about scientific language, not about farmers):

"The production volume of agriculturists is the reciprocal of the intellectual capacity of the producers."

also known as:

"The less intelligent the farmer, the bigger his potatoes."

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