Your understanding of a topic is a measure of how well you can explain it to another person to make them understand it, especially a child without previous formal knowledge of the topic. That's the summary of Feynman's learning technique.

Focus on Clarity Over Cleverness

When you can talk your way around something, it doesn't justify your understanding. All too often, we focus on learning about the technical jargon and frameworks that describe something without learning the topic itself. For example, below is a definition of Feynman's learning technique, somewhere on the internet:

"The Feynman Technique is a very famous method of learning that can unleash the potential of the brain to understand a complicated concept and develop deep learning tactics."

I may memorize that sentence and recite it whenever I'm asked about Feynman's learning technique. That doesn't mean I understand what I said. I may sound clever, but I don't have clarity. I can't talk about it without using the same group of words in that sentence and I can't develop original analogies to explain it to someone, especially a child.

An important goal of learning (for me) is:

To have an understanding that's so clear, yet deep enough to serve as a flexible building block I can apply together with the things I already know to solve problems. The problems may not even be in the same context as what I originally learned.

The Man And The Technique Called Feynman

Wait, who's Feynman, and why is he one to say how we could learn better?

Feynman was a Nobel prize-winning physicist. He developed the method of learning now named after him. Feynman's learning technique can be divided into 4 steps:

Step 1: Study the subject you want to learn. You may read about it, watch a video, do a project... whatever works for you.

Step 2: Explain what you think you now know after step 1 to a child. This step may seem frightening, but it's a good test for understanding. Children are inquisitive, they will have many questions. That will force you to explain to them in the clearest way possible, using the simplest words. But you may not always have a child around, or one that's willing to listen to your explanation of what Unix is and why it's still in use. However, there's a way I'll show below that you can use to substitute steps 2 and 3.

Step 3: Note the gaps and imbalances in your learning and fill them. You will find from step 2 that there are many shaky aspects of what you just learned or what you thought you knew because you can't explain to someone in simple terms, especially a child.

One way to do steps 2 and 3 together is to write. Yes, write about what you think you learned, like I'm doing now. Writing is a QA (quality assurance) system for understanding. It tests what you know, not what you think you know, and it exposes your ignorance (without apology). You may approximate a child's audience by using writing checkers. They check the simplicity of your writing based on what grade level can understand it. A classic example is the Hemingway App.

Step 4: Simplify and re-explain. After relearning to fill your knowledge gaps, you will be more comfortable with the topic. But you may need to repeat the steps many times to develop a deeper understanding. You can write about it again, refer to it in another one of your writings, or do a project where you'll apply your understanding of the topic.

There is a tendency of feeling like you haven't known enough, no matter how much you learn. This is a big mistake (from experience). Knowledge in any area is never static, it grows and it'll continue to be so. Remember, focus on clarity over cleverness or trying to know everything.