The Feynman technique: understand a topic by explaining it

What is the Feynman technique?

The Feynman technique is a way to check whether you really understand something: you explain it in simple words, as if to a twelve-year-old, without looking at your notes. Wherever your explanation stalls, goes vague or leans on a technical word you cannot define, you have found the part you do not yet understand. You then go back to your notes for that point only.

It is named after Richard Feynman, the Nobel Prize-winning American physicist famous for making hard ideas sound obvious. He never wrote down a four-step method; the name describes a way of working inspired by his insistence on clarity. The principle matches what learning research has long shown: producing an explanation forces you to organise what you know, while rereading only makes you feel that it is organised already.

How do you use the Feynman technique step by step?

The Feynman technique has four steps. Pick one specific concept. Explain it on paper or out loud with your notes closed, using short sentences and one example. Mark every point where you got stuck and go back to the source for those points only. Finally, rewrite the explanation more simply, until it holds together without a single word you could not define.

A session takes fifteen to thirty minutes per concept. Do not start with “chapter 4”: that is too broad for an explanation to reveal anything. “Why does the Moon have phases?” or “what does a derivative measure?” is the right size.

• 1. Choose — one concept that fits in a question: “How does photosynthesis work?”
• 2. Explain — notes closed, on a blank page or out loud, with a concrete example.
• 3. Find the gaps and go back — underline every hesitation, then reopen your notes on those passages only.
• 4. Simplify — rewrite the explanation, swap jargon for an image or comparison, and try again without your notes.

What does the Feynman technique look like on a real topic?

Take photosynthesis in biology. Your first attempt says: “Plants turn light into energy using chlorophyll.” Reading it back, you spot two gaps: you cannot say what goes in and what comes out, or where the reaction happens. You reopen your notes, write down carbon dioxide, water, glucose, oxygen and chloroplast, then explain again with an image: a factory that takes in air and water and makes sugar using sunlight.

In maths, the same approach works on derivatives. If your explanation stops at “you apply the formula”, you have not understood it. A good version says a derivative measures how fast a quantity is changing, and illustrates it with a car’s speed at one precise moment. In history, explain the causes of an event to someone who knows nothing about the period: you will quickly see whether you can connect the facts or only list them.

Which subjects is the Feynman technique best for?

The Feynman technique is most useful for topics where you need to understand a mechanism or a line of reasoning: physics, chemistry, biology, maths, economics, philosophy, and causes and consequences in history. It is much less useful for material that simply has to be memorised, such as foreign-language vocabulary, dates, verb tables or raw formulas. There is nothing to understand there, only something to remember.

So split the work. Use Feynman to build understanding, then use memory tools to keep it: questions, flashcards and spaced reviews. A concept you understood but never revisited still fades, only a little more slowly.

What mistakes make the Feynman technique useless?

The most common mistake is explaining with your notes open, or straight after reading them: you end up reciting sentences you just saw instead of testing your understanding. Close the notes and wait a few minutes first. The second mistake is keeping the textbook’s vocabulary. If “osmosis” appears in your explanation, you must be able to say what it means without using another technical word.

The third mistake is choosing a concept that is too big. Explaining “the French Revolution” produces a summary, not a test. Finally, many students stop at step two, happy to have written something. The real gain comes from steps three and four: going back to the source on specific gaps, then explaining again more simply.

• Notes open while you explain.
• Textbook terms copied without being able to define them.
• A concept the size of a whole chapter.
• No second, simpler version.

How can Study-Genie help with the Feynman technique?

Study-Genie helps most at step three, when you need to check your explanation. You upload your course (a PDF, a photo of handwritten notes, slides, a recorded lecture or pasted text) and the app turns it into a structured study sheet, which you can also read as a mind map. Compare your explanation with that sheet to see what is missing. You can also paste your explanation into the AI chat, which has your course in context, and ask what is wrong or imprecise.

Once the concept makes sense, move on to memory. A quiz generated from the same course tests you, every answer comes with an explanation, and the questions you got wrong come back first when you retake it. On iPad, the stylus notebook lets you write your explanation by hand. Every new account can try Essential free for 7 days with no card, then keep it for €2 per 28-day cycle.