I finally figured out a way to test whether you have taught an idea or you have only taught a definition…You say, 'Without using the new word which you have just learned, try to rephrase what you have just learned in your own language.
Striped of jargon and terminology, it quickly becomes clear what you actually understand and what you’ve just memorised.
Here’s how to put the technique into practice:
1) Write down everything you know about a topic.
2) Teach that topic to a child.
3) Identify the gaps in your knowledge.
4) Go back to your source material.
If you don’t have access to a child, an imaginary one will do. Or you can use the XKCD simple writer, a writing app that restricts you to just the one thousand most common words in the English language.
It’s also an excellent way of detecting bullshit, nonsense masquerading as sense. If someone is incapable of explaining an idea without resorting to big words and unwieldy language, there is a very good chance they’re talking bullshit.
The Feynman Technique also explains why I love teaching my own young kids. Not only does it expose gaps in my own understanding, it also reminds me that my ongoing memory disorder may make it hard for me to remembering facts, it doesn't stop me from understanding ideas.