# Feynman Technique

> Check that you understand something by explaining it in plain words.

Chapter IV, Communication · 4.04 · Origin: Attributed to Richard Feynman · Time: 20 to 40 min · Solo

**Use it when** you want to check whether you really understand something.

Interactive workspace: https://kogu.tools/tools/feynman-technique

## Abstract

It's easy to confuse knowing the words with understanding the idea. You recognise the terms and can repeat the definitions, and then a friend asks a simple question and you can't answer it. The Feynman Technique finds those gaps by having you explain the idea simply, as if to a twelve-year-old.

Wherever you reach for jargon or start waving your hands, you've found something you don't understand yet. Go back to the source, fill the gap, and try the explanation again.

## Method

1. **Name the concept.** Write the idea you want to understand at the top of a blank page.
2. **Explain it to a twelve-year-old.** Use short sentences and everyday words. If you need a technical term, explain it straight away.
3. **Find the gaps.** Mark every place you got stuck, leaned on jargon or couldn't say why something is true.
4. **Go back to the source.** Read up on those gaps until you can explain each one plainly.
5. **Simplify and add an analogy.** Rewrite the explanation. Compare the idea to something familiar and cut any word that isn't needed.

## When to use it

- You're learning something hard and want to know if it has actually sunk in.
- You have to explain a technical subject to people outside your field.
- Your writing is accurate but people say it's hard to follow.

## Common pitfalls

- Simplifying until the explanation is wrong. It should still be true when it's plain.
- Skipping the gaps step because the first draft felt fine.
- Chasing a readability score. It only measures word and sentence length.
- Explaining to an imaginary expert instead of a curious beginner.

## References

- Feynman, R. P. (1985). Surely You're Joking, Mr. Feynman! W. W. Norton.
- Gleick, J. (1992). Genius: The Life and Science of Richard Feynman. Pantheon Books.
- Flesch, R. (1948). A new readability yardstick. Journal of Applied Psychology, 32(3), 221 to 233.