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How To Learn New Subjects Easily - The Feynman Technique

12 November 2019 | 4 min read | Read more about Learning


Who is Richard Feynman?

Richard Phillips “Dick” Feynman was an American theoretical physicist[1], recipient of the Nobel Prize in Physics (1965), named one of the 10 greatest physicists of all time[2], and author of multiple books.

That introduction of Mr. Feynman does certainly not serve his achievements justice, but knowing what he accomplished in physics does not relate to the topic of this article, namely the ‘Feynman Technique’.

Why is the technique named after Feynman?

In “Feynman’s Lost Lecture: The Motion of Planets Around the Sun”[3], David Goodstein writes

Feynman was a truly great teacher. He prided himself on being able to devise ways to explain the most profound ideas to beginning students. Once, I said to him, “Dick, explain to me, so that I can understand it, why spin one-half particles Fermi-Dirac statistics”. […] Feynman said, “I’ll prepare a freshman lecture on it.” But he came back a few days later to say, “I couldn’t reduce it to freshman level. That means we don’t really understand it”.

And this truly is the essence of the Feynman Technique. If you can’t explain something to someone who knows little to nothing about it, you don’t understand it yourself.

In the biography that James Gleick wrote, “Genius: The Life and Science of Richard Feynman”, something similar is said about how Richard Feynman learned what he didn’t know.“He [Feynman] remained ignorant of the basic literature and unwilling to even read through the papers of Dirac or Bohr. This was now deliberate”. Doing so seems counter-productive, right? So what did he do?

He opened a fresh notebook, and on the title page he wrote Notebook Of Things I Don’t Know About. Following that, he

[…] reorganized his knowledge. He worked for weeks at disassembling each branch of physics, oiling the parts, and putting them back together, looking all the while for the raw edges and inconsistencies. He tried to find the essential kernels of each subject.

So to explain, what he did was find the most important parts of each subject, completely reorganizing the way the subject is structured in his mind. He looked for holes in his understanding and tried to fill them.

Looking for gaps in your understanding is the exact point of the Feynman Technique. It is not possible to explain something in such simple terms that someone with little to no knowledge of the subject can understand it if you do not understand the subject well enough yourself.

Using the Feynman Technique

The Four Steps

  1. Name it — write the name of the concept that you’re trying to learn on the top of the page.
  2. Explain it — Write an explanation of the concept on the page. This explanation should be so simple that someone who has little to no knowledge of the topic can understand it. Using simple analogies works incredibly well here. Focus on what you don’t understand yourself; the gaps in your understanding are crucial to identify.
  3. Review it — When you’ve identified the gaps in your knowledge, you go back and review what it is that you don’t understand.
  4. Repeat it — Now you simply repeat steps two and three until your explanation is satisfactory.

Why does it work?

Like I wrote earlier, it is not possible to explain something in such simple terms that someone with little to no knowledge of the subject can understand it if you do not understand the subject well enough yourself.

When trying to explain a subject in your own words, it’ll be almost impossible if you don’t understand it fully. What usually happens is that you start citing the textbook almost word for word. That means you’ve found a gap in your understanding.

Until you can explain the subject in your own words, you don’t understand it well enough.

My experience with the Feynman Technique

I don’t like writing about nor recommending things that I haven’t tested myself. Otherwise, how would I endorse it?

I use the Feynman Technique while studying. It helps me understand the subject at hand. I have found that asking myself questions like “what does this mean?” or “what could be an example of this?” as if someone were asking me those questions works well because it is easy to write notes answering those questions.

To illustrate what I mean, here is an example of a question from my notes on Number Theory:

Example of the Feynman Technique

Note: The example is taken out of context; the whole page is too long to include here. I had described using modulo earlier in the same way. The above is a description of using ‘arithmetic modulo m’.

As a last note, I want to say that I wholeheartedly endorse his book “Surely You’re Joking Mr. Feynman!” as well as “Six Easy Pieces“. I have read both of them and I think that they are absolutely fantastic. Richard Feynman is not in any way a boring physicist, he is actually quite the character!

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