Find the Gap

What it does

Finds the thing you think you understand and don’t — by making you explain it out loud and then probing exactly where the explanation goes vague. The dangerous gaps aren’t the ones you know about; they’re the ones hiding under a sentence you can say fluently without understanding.

When to use it

• Everything makes sense while you read it and dissolves in the exam
• You can follow the worked example and freeze on a new one
• Before a test, an interview, or teaching something to someone else

The skill

Act as an examiner probing my understanding. HARD RULES: your job
is finding what I don't know, not reassuring me — be direct about
every gap you find; never invent facts to test me on, and if you
are unsure whether something I said is wrong, say you're unsure
rather than ruling. When I use a technical word, make me define it
before you accept it. Never let a fluent-sounding answer pass
unexamined — fluency is what hides gaps. Don't be harsh about me,
just precise about the answer.

The topic: [WHAT I'M CLAIMING TO UNDERSTAND]
What it's for: [EXAM / WORK / TEACHING SOMEONE]
My explanation of it, in my own words, right now, without looking
anything up: [WRITE IT OUT — this is the raw material]

Now:
1. PROBE IT: pick the three vaguest points in what I wrote and
   ask me about each — one at a time, waiting for my answer. Go
   after phrases that sound right but do no work, and after any
   technical term I used without defining.
2. THE WHY CHAIN: take one central claim and ask "why" three
   times in a row. Understanding usually runs out around the
   second or third, and where it runs out is the real edge.
3. THE EDGE CASE: give me a situation my explanation doesn't
   obviously cover and ask what happens. Working knowledge
   handles new cases; memorised knowledge doesn't.
4. THE VERDICT: what I actually understand, what I can recite
   without understanding, and what's simply missing. Be specific
   — "shaky on X" beats "review chapter 4".
5. WHAT TO DO ABOUT EACH GAP: for every one found, what kind of
   fix it needs — a definition, a worked example, going back a
   step to something underneath it — and what to check it against
   in a real source rather than against you.

Example output

[TO FILL AFTER TESTING]

Tweaks

• Write your explanation before opening any notes. The gaps live precisely in what you can’t produce unaided
• Asking “why” three times is the sharpest tool here — most understanding is one layer deep and thinks it’s three
• A gap found a week early is a small job; the same gap found in an exam is the exam
• If it says you understand something, that’s evidence, not proof. Verify the substance against a real source