The Feynman Technique: Step by Step, With Worked Examples

The Feynman technique is a study method where you explain a concept in simple words, as if you were teaching it to someone who knows nothing about it, then use the spots where you get stuck to find what you don't really understand. You fill those gaps from your notes, simplify again, and repeat until your explanation is clear and correct.

It's named after the physicist Richard Feynman, and it's one of the fastest ways to tell the difference between knowing the words and knowing the idea. Below you'll find the steps, why it works, three full worked examples (biology, economics and maths), a template you can copy and the mistakes to avoid.

Who was Richard Feynman, and did he invent this?

Richard Feynman was an American theoretical physicist. He shared the 1965 Nobel Prize in Physics for work on quantum electrodynamics, and he was famous as a teacher. His undergraduate lectures at Caltech were published as The Feynman Lectures on Physics, and he was well known for explaining hard ideas with plain language and everyday examples.

He also had a strong view that knowing the name of something is not the same as understanding it. That attitude runs through his popular books and talks.

Here's the honest part: Feynman never wrote down a four-step "Feynman technique". The numbered method you see online is a later popular formulation, put together by other people to capture how he approached learning. It carries his name because it fits his style, not because he designed it as a study system. That doesn't make it less useful. It just means you should treat it as a practical method, not a historical document.

Why does the Feynman technique work?

It exposes the illusion of understanding

Most of us think we understand things better than we do. Rozenblit and Keil (2002), published in Cognitive Science, called this the illusion of explanatory depth. People rated how well they understood everyday devices like zips and toilets, then tried to explain how they work step by step. After trying, they lowered their ratings. The act of explaining showed them the gaps.

Study works the same way. After a lecture, photosynthesis feels clear. Ask yourself to explain it start to finish without notes and the fog appears.

It's active recall

You explain from memory first, then check. That is retrieval practice, which the research strongly supports. Our guide to active recall covers the evidence in detail.

It forces self-explanation

Chi and colleagues (1989), in Cognitive Science, found that students who explained worked examples to themselves while studying, saying why each step happened, learned more than students who didn't. The Feynman technique builds that habit in: every step needs a because.

It cuts through jargon

Technical terms are useful shortcuts, but they can also hide confusion. If you can only explain "osmosis" by saying "it's diffusion across a membrane", you might be repeating a definition rather than understanding it. Explaining without the jargon reveals which.

The Feynman technique step by step

Step 1: Choose one concept

Write the name of the concept at the top of a blank page. Keep it small. "Genetics" is too big. "How a recessive trait can skip a generation" is right.

Step 2: Explain it simply, from memory

With your notes closed, write or say an explanation aimed at someone younger, say a student a few years below you, or a curious 12 year old. Use short sentences and everyday words. Include an example.

Don't stop to check anything. Write until you run out.

Step 3: Find the gaps and go back to the source

Read your explanation and mark every spot where you:

• got stuck or skipped a step
• used a technical word without explaining it
• wrote "basically", "somehow" or "it just does"
• weren't sure if it was right

Now open your notes or textbook and fix exactly those parts. Don't reread the whole chapter. Target the gaps.

Step 4: Simplify and use an analogy

Rewrite the explanation, shorter and clearer, with the gaps filled. Add an analogy or a concrete example. If a sentence is long and tangled, that usually means the thinking behind it is tangled too.

Optional step 5: Test it

Explain it to a real person, record it, or try an exam question on it. If someone asks "but why?" and you can answer, you've got it.

Worked example 1: Biology (osmosis)

First attempt, from memory

Osmosis is when water moves from high concentration to low concentration across a membrane. So if you put a cell in water, water goes in. In salty water it goes out. It's basically diffusion but for water.

Gaps marked

• "High concentration to low concentration": high concentration of what? Water or salt? This is ambiguous and it's the most common place students lose marks.
• "Across a membrane": what kind of membrane, and why can't the salt just move instead?
• "Water goes in": then what happens to the cell? Is it different for plant and animal cells?
• "Basically diffusion": that's a definition, not an explanation.

After checking notes and simplifying

Osmosis is the overall movement of water across a partially permeable membrane, from a dilute solution to a more concentrated one. "Partially permeable" means the membrane lets water molecules through but blocks bigger solute particles like sugar.

Think of it like this: water spreads out towards where there's relatively less water and more dissolved stuff. The dissolved particles can't cross, so the water moves instead.

Put a red blood cell in pure water and water moves in, because the inside of the cell is more concentrated. The cell swells and can burst. A plant cell in the same water swells too, but its cell wall stops it bursting, so it becomes firm, or turgid. In very salty water, both lose water and shrink.

Now the explanation names the membrane, says which way water moves and why, and covers both cell types. Each of those fixes came from a gap in the first attempt.

Worked example 2: Economics (price elasticity of demand)

First attempt, from memory

Price elasticity of demand is how elastic demand is when the price changes. Elastic means it changes a lot and inelastic means it doesn't. Petrol is inelastic.

Gaps marked

• "How elastic demand is" uses the word to define itself.
• No formula, so no way to tell whether something is elastic.
• Why is petrol inelastic? No reason given.
• Nothing about why anyone cares, for example total revenue.

After checking notes and simplifying

Price elasticity of demand measures how strongly the quantity people buy reacts when the price changes. You work it out as the percentage change in quantity demanded divided by the percentage change in price.

If the answer (ignoring the minus sign) is more than 1, demand is elastic: people react a lot. If it's less than 1, demand is inelastic: people keep buying roughly the same amount.

The main driver is substitutes. Petrol is usually inelastic in the short term because most drivers can't quickly switch to something else, so they keep filling up even when prices rise. One particular brand of chocolate bar is more elastic, because if it gets pricier you just grab a different one.

Why it matters: if demand is inelastic, a business can raise its price and still earn more total revenue, because sales barely fall. If demand is elastic, raising the price can cut total revenue.

The second version can actually answer an exam question. The first couldn't.

Worked example 3: Maths (the derivative from first principles)

First attempt, from memory

The derivative is the gradient. For x squared it's 2x because you bring the power down and take one off. From first principles you use the limit formula.

Gaps marked

• "Gradient" of what? A curve doesn't have one single gradient.
• The power rule is a shortcut, not an explanation of why the answer is 2x.
• "Use the limit formula" without saying what the formula does or why there's a limit.

After checking notes and simplifying

A straight line has one gradient everywhere. A curve doesn't: it gets steeper or flatter as you move along it. The derivative tells you the gradient of the curve at one exact point.

To find it, pick a point x on the curve and a second point a tiny distance h further along. The gradient of the straight line joining them is rise over run: (f(x+h)−f(x))/h. As you slide the second point closer, making h smaller and smaller, that line gets closer to the curve's true gradient at x. The limit as h goes to 0 is the derivative.

For f(x) = x², the rise is (x+h)² minus x², which is 2xh + h². Divide by h and you get 2x + h. As h shrinks to 0, that becomes 2x. So the gradient of y = x² at any point is 2x. At x = 3, the curve is climbing with a gradient of 6.

The power rule ("bring the power down, take one off") is just a shortcut that gives the same answer without doing the limit every time.

The rewrite explains why the limit is there, and it shows where the shortcut comes from. That's the difference between following a rule and understanding it.

A Feynman technique template you can copy

Copy that into a notebook page or a document and fill it in for each concept. Your final versions make excellent revision notes, and the "Gaps" column shows you which topics need the most time. If you're rethinking how you write notes in general, our guide on how to take notes shows how to build questions into them from the start.

When should you use the Feynman technique?

For pure memorisation, flashcards and spacing do the job better. For understanding, the Feynman technique is hard to beat. Most students get the best results combining them: explain the concept to understand it, then make a few flashcards to keep the key facts fresh.

Variations that work well

Teach a friend. A real listener asks questions you never thought of. Swapping concepts with a classmate, ten minutes each, doubles the value. If you want to make this a regular thing, see our guide on how to start a study group.

Voice memo. Record yourself explaining, then listen back while following your notes. Pauses and "ums" mark the gaps.

Rubber duck. Programmers explain their code line by line to a rubber duck to find bugs. It works for essays and proofs too. The listener doesn't need to understand. You do.

Exam answer version. For a 6 or 8 mark explain question, write your Feynman explanation, then trim it into an exam answer that hits each mark.

Whiteboard. Explain while drawing diagrams. Visual subjects like biology, physics and geography benefit most.

What are the most common Feynman technique mistakes?

Explaining with your notes open. Then you're reading, not explaining. Write first, check second.

Picking a topic that's too big. "Explain the whole of Year 12 chemistry" ends in a vague mess. One concept per page.

Using the jargon anyway. It's fine to use technical terms in the final version, since examiners expect them. But you must be able to say what each one means.

Simplifying until it's wrong. "Plants eat sunlight" is simple and wrong. Simple means clear, not inaccurate. Check your final version against the textbook.

Skipping the rewrite. Finding gaps is only half the job. The learning happens when you fix them and explain again.

Doing it once. Come back in a few days and explain it again from memory. The second attempt is usually much faster, and the parts you forgot again are the ones to flashcard.

How to do the Feynman technique with StudyDork

The Feynman technique only needs paper, but it does need your full attention, because the whole point is to notice where your explanation wobbles. A phone buzzing every few minutes makes that hard.

• One concept per block. A free StudyDork Pomodoro session runs 20 minute focus blocks with 5 minute breaks. That's about right for one full round: explain, find gaps, fix, rewrite. StudyDork Pro adds longer splits, such as 50 minutes of focus and 10 of break, if you want to work through several concepts at once.
• Notes closed, phone blocked. Any session can block the apps you choose until it ends, so the only thing to do is explain.
• Explain to your clan. If you study with friends in a clan, use the clan chat between sessions to post a concept and ask someone to explain it back, or to poke holes in yours.

Explain it, then you'll know it

The Feynman technique is uncomfortable in a useful way. Within five minutes it shows you that some of what you "know" is just familiar words. That's not bad news. It's a map of exactly what to study next.

Pick one concept from this week's classes. Write its name at the top of a page, close your notes and explain it like you're talking to a younger sibling. Circle the parts where you hesitated. Those circles are worth more than another hour of rereading.