The Feynman Technique: Learn Anything by Teaching It

Richard Feynman won a Nobel Prize, cracked safes for fun, and played bongo drums in a samba band. He was also famous for explaining complex physics in plain English—something most experts can't do. His secret wasn't just brilliance. It was a learning method that forces genuine understanding. If you can't explain something simply, you don't really know it. This guide breaks down the Feynman Technique and shows you how to use it for any subject.

What Is the Feynman Technique?

The Feynman Technique is a learning method where you explain a concept as if teaching it to someone with no background knowledge. The act of simplifying exposes what you actually understand versus what you've merely memorized.

The core principle: complexity is a symptom of incomplete understanding.

When you truly grasp something, you can explain it without jargon, analogies come naturally, and you can answer "why" questions at multiple levels. When you can't explain it simply, you've found exactly where to focus your study.

The 4 Steps of the Feynman Technique

Step 1: Choose a Concept

Pick one specific topic, theorem, process, or idea. Be precise—not "economics" but "how supply and demand determine price." Not "photosynthesis" but "how plants convert light into glucose."

Write the concept at the top of a blank page.

Step 2: Explain It in Plain Language

Write an explanation as if teaching a 12-year-old. No jargon. No technical terms without definitions. Use:

• Simple words
• Short sentences
• Concrete examples
• Analogies to familiar things

If the concept is "how TCP ensures reliable data transfer," don't write "TCP uses acknowledgment packets and sequence numbers for flow control." Instead: "Imagine sending a letter and waiting for a reply that says 'got it' before sending the next one. If no reply comes, you send the same letter again. That's basically what TCP does with data."

Step 3: Identify Gaps and Return to Source

As you write, you'll hit walls. Places where your explanation gets vague, hand-wavy, or collapses into jargon. These gaps are the entire point.

Mark each gap. Return to your source material—lecture, textbook, video—and study specifically that piece. Don't re-read everything. Target the weak spots.

Then try explaining again.

Step 4: Simplify and Use Analogies

Once your explanation works, make it better. Can you use fewer words? Is there a more intuitive analogy? Could you draw a simple diagram?

Feynman himself was famous for this. He explained quantum electrodynamics using arrows and clocks. He described rubber O-rings failing in cold weather by dropping one in ice water during a congressional hearing.

The goal isn't dumbing down—it's clarifying. A good simple explanation captures the essence without losing accuracy.

Why the Feynman Technique Works

It Exposes Illusions of Competence

Reading and highlighting feel productive. You recognize the material, so it seems learned. But recognition isn't recall, and recall isn't understanding.

Teaching forces production. You can't fake your way through an explanation. Either the words come or they don't. Either the logic flows or it breaks. The technique ruthlessly exposes the gap between "this looks familiar" and "I can use this."

It Creates Deeper Encoding

Translating ideas into your own words requires processing at a deeper level. You're not copying—you're reconstructing. This elaborative encoding creates stronger, more durable memory traces than passive review.

It Builds Transferable Understanding

Jargon-based knowledge is brittle. It works for test questions that use the same terminology but fails when the context changes. Plain-language understanding transfers across contexts because it's built on core principles, not surface phrasing.

It Makes Gaps Obvious

Most study methods let you skip over confusion. You read a paragraph you don't fully understand, nod, and move on. The Feynman Technique makes this impossible. When you try to explain, confusion becomes visible—a sentence you can't finish, an analogy that doesn't quite work, a "why" you can't answer.

Feynman Technique Examples

Example 1: Biology — How Vaccines Work

First attempt (too jargon-heavy): "Vaccines introduce antigens that stimulate the adaptive immune system to produce memory B cells and T cells, providing immunological memory against future pathogen exposure."

Gap identified: What actually happens inside the body? Why does showing the immune system a harmless piece help?

Feynman-style explanation: "Your immune system is like a security team that remembers faces. When a virus attacks, the team has to figure out who the bad guy is—which takes time. A vaccine shows your security team a mugshot of the bad guy in advance. It's not the real criminal, just a photo (a harmless piece of the virus). Now when the real virus shows up, your team recognizes it immediately and takes it down before it can do damage. That's why vaccinated people often don't get sick—their security team already knows the face."

Example 2: Computer Science — Recursion

First attempt (circular): "Recursion is when a function calls itself to solve smaller instances of the same problem."

Gap identified: Why would calling yourself help? When does it stop?

Feynman-style explanation: "Imagine you're in a line of people, and someone asks 'how many people are behind you?' You could count everyone yourself. Or you could tap the person behind you and ask 'how many people are behind you?' They do the same thing—tap and ask. This continues until someone at the back says 'zero, I'm last.' Then each answer flows forward: 'zero' becomes 'one' becomes 'two' and so on until you have your answer. That's recursion: solving a problem by asking someone to solve a smaller version, until someone has an answer so simple they don't need to ask anyone."

Example 3: Economics — Inflation

First attempt (vague): "Inflation is when prices go up because there's too much money chasing too few goods."

Gap identified: Why does more money cause higher prices? What's the mechanism?

Feynman-style explanation: "Imagine a small island with 10 people and $100 total. A coconut costs$1. Now a plane drops another $100 on the island—suddenly there's$200 circulating among the same 10 people buying the same coconuts. Everyone has more money, so they're willing to pay more. The coconut seller realizes people will pay $2 now. Nothing changed about the coconuts—same taste, same supply. But the money became less rare, so each dollar buys less. That's inflation: not prices going up, but money going down in value."

Common Mistakes to Avoid

Using Jargon as a Crutch

If you catch yourself using a technical term, ask: "Could I explain what this term means?" If not, you've found a gap. Replace the term with its meaning, or mark it for study.

Explaining to an Expert (in Your Head)

The imaginary student matters. If you're mentally explaining to your professor, you'll skip steps and use shorthand. Explain to someone smart but unfamiliar with the topic—a curious friend from a different field.

Stopping at Surface Explanations

"Gravity pulls things down" is true but shallow. Push deeper: Why does mass attract mass? How did Einstein change Newton's view? The technique works at multiple levels—keep asking "why" until you hit bedrock.

Skipping the Writing

Thinking through an explanation feels similar to writing one. It's not. Writing forces precision. Thoughts can be vague; sentences can't be. Write it out, even if it feels slow.

How to Accelerate the Feynman Technique with AI

The hardest part of the Feynman Technique is getting started. Staring at a blank page, trying to explain something you just learned, is intimidating. This is where AI-generated summaries help.

Use Summaries as a Starting Point

Instead of starting from zero, start from a structured summary of your lecture or reading. This gives you:

• The key concepts already identified
• A logical structure to follow
• Language you can simplify further

Think of the AI summary as a first draft that's too formal. Your job is to translate it into plain English and fill in gaps.

The Digestly Workflow

1. Import your material: Paste a YouTube lecture link, upload a PDF, or add your notes.
2. Generate a summary: Get structured notes that identify the main concepts.
3. Pick one concept: Start with the most important or confusing idea.
4. Write your Feynman explanation: Use the summary as a reference, but explain in your own words.
5. Test yourself: Generate a quiz and see if you can answer without jargon.
6. Create teaching flashcards: Turn your plain-language explanations into cards for review.

Why This Works

The summary handles the "what"—identifying key concepts and structure. You handle the "why"—translating into genuine understanding. This division of labor makes the technique faster without losing its power.

If your Feynman explanation doesn't match the summary's claims, you've found a gap. Return to the source, study that specific piece, and try again.

Try it: Open Digestly

A Weekly Feynman Practice Schedule

Monday: Fresh Material

Watch or read new content. Generate a summary. Identify 2-3 concepts to Feynman.

Tuesday: First Explanations

Write Feynman explanations for each concept. Don't check sources yet—see what you actually retained.

Wednesday: Gap Hunting

Review your explanations. Mark every vague spot, jargon term, or shaky analogy. Return to sources for targeted study.

Thursday: Revision

Rewrite explanations with gaps filled. Simplify further. Add better analogies.

Friday: Teach Out Loud

Explain your concepts verbally—to a friend, rubber duck, or voice memo. Speaking reveals different gaps than writing.

Weekend: Quiz and Connect

Take a practice quiz. Write a short piece connecting this week's concepts to previous material.

FAQs

How long should a Feynman explanation be?

Short enough to fit on one page, long enough to cover the "why." For most concepts, 1-3 paragraphs works. If you need more, the concept might be too broad—break it into sub-concepts.

Can I use the Feynman Technique for math and equations?

Yes, but adapt it. Instead of explaining in words only, walk through the logic of each step. Why this operation? What does this symbol represent physically? A good test: can you explain why the equation makes sense, not just how to calculate it?

What if I'm studying alone with no one to teach?

Write as if teaching. Explain to an imaginary student, a rubber duck, or a voice recorder. The audience can be fictional—what matters is that you're producing an explanation, not just consuming information.

How is this different from summarizing?

Summarizing compresses information. The Feynman Technique translates it. A summary might use the same jargon as the source. A Feynman explanation must use plain language, which requires deeper processing.

How many concepts should I Feynman per study session?

Quality over quantity. One concept explained deeply beats five concepts explained superficially. Start with 1-2 per session and increase only if you're genuinely reaching understanding, not just producing words.

References

• Feynman, R. P. (1985). "Surely You're Joking, Mr. Feynman!" W. W. Norton & Company.
• Chi, M. T., De Leeuw, N., Chiu, M. H., & LaVancher, C. (1994). Eliciting self-explanations improves understanding. Cognitive Science, 18(3), 439-477.
• Dunlosky, J., Rawson, K. A., Marsh, E. J., Nathan, M. J., & Willingham, D. T. (2013). Improving students' learning with effective learning techniques. Psychological Science in the Public Interest, 14(1), 4-58.
• Roediger, H. L., & Karpicke, J. D. (2006). The power of testing memory: Basic research and implications for educational practice. Perspectives on Psychological Science, 1(3), 181-210.

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The Feynman Technique isn't just a study hack—it's a test for real understanding. If you can explain it simply, you know it. If you can't, you know exactly where to focus.

For related strategies, read our guides on active recall and spaced repetition.

Ready to try it? Import your next lecture, generate a summary, and practice explaining the key concepts in plain English with Digestly.