The physicist Richard Feynman was famous for explaining hard ideas in plain language. The study method named after him is a way of borrowing that habit: if you can explain something simply, without notes and without jargon, you understand it. If you cannot, the places where you get stuck show you what to study next.
The idea that explaining helps learning has good support. In a 2014 study, John Nestojko, Dung Bui, Nate Kornell and Elizabeth Bjork found that students who expected to teach a passage to someone else remembered it better and organized it more clearly than students who expected a test. Explaining is another form of retrieval: you have to pull the ideas out of memory and connect them.
The four steps
1. Pick a concept and write it at the top of a blank page
Keep it narrow. "Photosynthesis" is a good size; "biology" is not.
2. Explain it as if to a 12-year-old
Write or say the explanation in plain words, with no notes. Use short sentences, an everyday example and no technical terms you could not define. Jargon is where misunderstanding hides; a word you cannot explain is a word you are hiding behind.
3. Find the gaps and go back to the source
Wherever you got stuck, waved your hands or reached for a technical word, mark it. Go back to your notes or textbook for just those parts, then try the explanation again.
4. Simplify and use an analogy
Read your explanation back. Cut what is unnecessary and add an analogy that makes the idea concrete. If a classmate could follow it, you are done.
An example
First attempt: "Photosynthesis is when plants use chlorophyll to convert light energy into chemical energy through the light-dependent reactions and the Calvin cycle."
That sounds right, but it is mostly vocabulary. Ask what each part means, and the gaps appear: what is the chemical energy stored in? What happens in each stage?
After filling the gaps: "Plants make their own food. Their leaves catch sunlight with a green substance called chlorophyll. They use that energy to split water, then use the energy they captured to build sugar out of carbon dioxide from the air. The sugar is the plant's fuel, and the oxygen left over from splitting water goes into the air. It is like a solar-powered kitchen that turns air and water into food."
The second version is longer, but every sentence shows understanding, and writing it revealed exactly what the first version skipped.
Common mistakes
- Explaining with the notes open. Then you are copying, not recalling.
- Keeping the jargon. Technical terms are fine once you can define them. Until then, they hide gaps.
- Skipping step three. Finding the gaps is the whole point. Go back to the source every time.
- Doing it once. Explain the same concept again a few days later. If it comes out easily, it has stuck.
Ways to use it
- Alone: write the explanation on a blank page or record yourself saying it.
- With a friend: take turns explaining topics and asking "why?" after every answer.
- In class: teachers can ask students to explain a concept to a partner in plain words, then share the best analogies.
Feynman plus practice questions
The Feynman technique shows whether you understand an idea; practice questions show whether you can use it the way the test will ask. The two fit together: explain the concept, then answer a few questions on it. Our post on active recall versus rereading has more ways to build both into a study session, and Quizbot can make practice questions from the same notes you are explaining.
Summary
- Explain the concept in plain words, without notes.
- Where you get stuck is what you need to study.
- Repeat a few days later, and follow up with practice questions.
