This AI prompt stops AI from making things up without you noticing. It gives the model a way out, a line that tells it to say when it’s not sure. Then 4 more lines put every step of its math on the page where you can check it.

Teaching the model to say “I don’t know”

“Do not hallucinate” is right up there with “make me a billion-dollar app. Don’t make any mistakes.” You can type it, but the model can’t obey it.

It can’t tell when it’s making something up. The incorrect answer & the correct one come out in the same confident voice.

So what do you write instead? A thread on r/PromptEngineering asked exactly that, & the top comment is worth stealing:

If you are uncertain or lack sufficient information to answer
accurately, say so explicitly. Do not infer, speculate, or fill
gaps with plausible-sounding information. Cite your reasoning and
flag any claims that may be incomplete or unverified.

One line is doing most of the work here. “Say so explicitly.”

Picture where a model usually goes wrong. You ask about something it half knows. Halfway through the answer it runs out of real knowledge.

The one move left is to keep writing & hope you won’t notice. Every sentence comes out in the same steady voice, so you don’t.

“Say so explicitly” gives it a way out. It can stop & tell you.

A liar who sounds confident is harder to catch than one who says “I might be wrong.” The model’s “I’m not sure” is the only warning you’ll ever get that something’s invented.

Now look at the lines people paste at the end of their prompts. “Rate your confidence 0 to 100.” “Make sure every answer is 100% accurate.” “Do you understand?” Every one of them orders the model to sound confident, & that silences the only warning you had.

The prompt that stops AI from making up math

Keep the good part, the first line. Then there’s everything else models make up, the facts, the sources, the numbers.

Math matters here because the savings plan prompt runs on it. Both of its paths lean on compound interest, the debt growing against you, the savings growing for you. A model predicts what an answer should look like instead of calculating it, & a wrong total looks exactly like a right one. Add this to any prompt that asks for math:

1. Do the math one step at a time, month by month.
2. Show every number you use and where it came from.
3. Show the result of each step before moving to the next.
4. If you are not sure about any number, say "I'm not sure"
   and ask me. Do not guess.

Now every step is on the page where you can check it. That’s why the savings plan prompt says “show your math.” Math is just the example. Reword the 4 steps & the same trick works on facts, sources, dates, quotes.

The model will still guess sometimes. The win is getting it to raise its hand before it does.

Top comment by u/Appropriate-Owl-2696 on r/PromptEngineering. Link

When you need AI to check what it already said

To check an answer after it’s written, the self-check prompt makes the model name its 3 weakest assumptions. For research you plan to quote, the cite sources prompt shows where each fact came from.

This teardown first ran in issue 6.