Feynman Technique Prompt for Studying

What this prompt does

A Feynman technique prompt checks an explanation you wrote from memory against the source you learned it from, then tells you where the explanation is wrong, where it skips something the source treats as essential, and where it goes vague at the point that needed a reason. It doesn't fix the explanation. Fixing it is your job, and the fixing is where the learning happens.

The direction matters. If you came here wanting an AI to explain a topic simply, as if to a 12-year-old, that's the explain a concept prompt, which has a variation for exactly that. There the model explains and you read. Here you explain and the model reads, with your source open beside it.

The technique is named after the physicist Richard Feynman, famous for making hard physics sound simple. Strip the popular versions down and one move is left: explain the idea in plain words to someone who never took the class, then find where the explanation breaks. The prompt takes the second half, because you're the worst judge of your own explanation.

That isn't a figure of speech. In 2002, Leonid Rozenblit and Frank Keil asked 16 Yale graduate students to rate how well they understood everyday devices such as a zipper, a flush toilet and a cylinder lock on a 7-point scale. Then each wrote a step-by-step causal explanation of four of them and rated themselves again. The ratings dropped, and many participants "reported genuine surprise and new humility at how much less they knew than they originally thought." The authors called it the illusion of explanatory depth, and found it far stronger for explanations than for facts, procedures or stories.

So a flashcard prompt won't catch it. Cards test whether you remember facts; this tests whether you can say how something works, the kind of knowledge people overrate most.

The prompt

I'm studying [TOPIC]. Below are a SOURCE and an EXPLANATION of the topic that was written from memory with the source closed. Check the explanation against the source.

**Who the explanation is meant for:** [e.g. "a friend who skipped this class" / "a first-year student in another subject"]

Rules:
- Judge only against the source. If the explanation says something the source doesn't cover, list it under "Can't check" instead of judging it from your own knowledge.
- Don't rewrite the explanation, don't explain the topic, and don't praise or grade the explanation.
- Quote the exact source sentence for every point you raise.

Report in this order:
1. **Wrong:** statements the source contradicts. Quote the explanation's words, then the source sentence.
2. **Missing:** ideas the source treats as essential that the explanation leaves out. One line each, with the source sentence.
3. **Vague:** filler ("basically", "somehow", "it just", "kind of") or hand-waving where the source gives a reason or a mechanism.
4. **Borrowed words:** technical terms the explanation uses without saying what they mean.
5. **Can't check:** claims the source doesn't cover.
6. **Three questions** the source answers and the explanation doesn't. Questions only, no answers.

If a section is empty, write "None" and move on.

<source>
[PASTE THE TEXTBOOK SECTION, LECTURE NOTES, OR ARTICLE]
</source>

<explanation>
[PASTE WHAT YOU WROTE OR SAID FROM MEMORY]
</explanation>

How to use it

1. Pick one concept, not a chapter. "What causes the seasons" works. "Unit 3: Earth science" doesn't, because an explanation of a whole unit turns into a summary, and a summary can be accurate while hiding every gap. For a whole unit, build a revision sheet with the study guide prompt first, then run this on the three concepts you'd least like to explain out loud.
2. Close the source, then explain. Type it or say it into your phone's voice input, pitched at the person you named in the prompt. If you catch yourself reaching for the textbook's exact phrasing, stop and say it your way: a memorized term can stand in for an idea you don't have.
3. Paste the source itself, not a link or a topic name. Without one, the model grades you against its own memory, which can be just as confidently wrong as your explanation was. The research guide's first technique, handing over the source, covers why. Cut a long chapter down to the section on your concept.
4. Don't say you wrote it. The prompt calls it "an explanation that was written from memory" and bans praise, on purpose. When Anthropic researchers tested five AI assistants in 2023, the models gave more positive feedback when the user said they wrote the text or liked it, across math solutions, arguments and poems. You want the feedback a stranger's draft would get.
5. Answer the three questions before you open the source again. Out loud or on paper. Then re-explain only the parts that came back Wrong or Missing and run the prompt again. Stop when both sections come back "None."

Example output

Inputs: topic "what causes the seasons"; meant for "a friend who skipped this class"; source: the full text of NASA Space Place's What Causes the Seasons? page, pasted in. The explanation took about a minute:

"We get summer when the Earth is closer to the Sun and winter when it's farther away. The Earth's axis is tilted, which basically makes some places get more sun. That's also why summer days are longer."

1. Wrong "We get summer when the Earth is closer to the Sun." Source: "in the Northern Hemisphere, we are having winter when Earth is closest to the Sun and summer when it is farthest away!"

2. Missing

• What the tilt changes: "It is summer in June in the Northern Hemisphere because the Sun's rays hit that part of Earth more directly than at any other time of the year."
• Opposite seasons: "As the poles are on opposite ends of Earth, they experience opposite timing for the seasons."
• Why the pattern repeats: "As Earth orbits the Sun, its tilted axis always points in the same direction."

3. Vague "basically makes some places get more sun": which places, at what time of year, and what changes about the sunlight? The source answers all three.

4. Borrowed words "axis": used without saying what it is. Source: "Earth's axis is an imaginary pole going right through the center of Earth from 'top' to 'bottom.'"

5. Can't check "summer days are longer": the source doesn't discuss day length.

6. Three questions

1. In which month is Earth closest to the Sun, and which season is the Northern Hemisphere having then?
2. When it's summer in the Northern Hemisphere, what season is the Southern Hemisphere having, and why?
3. Why does it matter that the axis always points the same way while Earth goes around the Sun?

Three sentences produced seven findings. The first is the very misconception NASA's page stops to correct ("Many people believe that Earth is closer to the Sun in the summer"), and rereading wouldn't have caught it: the student would have nodded along to every line. The day-length claim is true. It sits under Can't check only because this source never mentions it, and the model didn't rewrite a word of the explanation. The second attempt is still the student's to make.

Variations

When you said it out loud

Add "The explanation was spoken and transcribed by voice input. Ignore false starts and repeated words, but still flag fillers like 'basically' and 'somehow' where a reason should be." Talking is harder to polish than typing, which is the point. Without that line, the Vague section fills up with every "um."

For a process or a derivation

For anything with ordered steps (a proof, a lab method, the Krebs cycle), add "Also check the order. List any step the explanation skips, swaps, or merges with another, quoting the source's version of that step."

The second round

Paste the first report above the new attempt and add "Compare this new explanation with the report above. For each earlier finding, say Fixed or Still there. Then list anything new under the same six headings." Without it, the model starts fresh and may hand you new nitpicks instead of saying whether the real problems are gone.

When the source is your own notes

Lecture notes have gaps of their own. Add "The source is my lecture notes, which may be incomplete. Under Can't check, also list any place where the notes themselves seem to skip a step, so I can look it up in the textbook."

Common pitfalls

• Don't ask for the right answer afterwards. One follow-up like "so what's the correct explanation?" undoes the no-rewrite rule, and you're reading again. Reading is what produced the confident wrong version. Go back to the source yourself.
• Don't write the explanation with the source open. You'll paraphrase instead of recall, and the report will come back clean on knowledge you don't have yet.
• Don't hide behind the textbook's vocabulary. "The mitochondria is the powerhouse of the cell" can be recited by someone who couldn't say what the cell is powering or how.
• Don't treat "None" under Missing as proof you've got it. The check runs against one source. If that source is a two-paragraph summary, a clean report means you can match a summary. Before an exam, check against what the exam is built on.
• Don't use it on an argument. A thesis you plan to defend isn't an explanation, and it fails in different ways. The devil's advocate prompt is built for that.

Who uses this prompt

• Students revising for exams in subjects where the questions start with "explain" or "why," not "name" or "list." More in prompts for students.
• People new to a field at work, checking a methods document before they explain it to a client.
• Anyone about to present or teach, who'd rather find the gap before the audience does.
• Self-learners with a textbook and no tutor, nobody around to ask "and why does that happen?"

ChatGPT, Claude, and Gemini all run it unmodified. The section that's easiest to skim past is Borrowed words, because it flags the terms you're proudest of knowing. In the seasons example, it's the one that caught "axis": the word the whole explanation leaned on, and the one thing it never defined.