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How to tell if an AI answer is true in 30 seconds

The Bluff Filter is this kind of check, on one page. Take it with you →

AI sounds exactly as confident when it’s wrong as when it’s right. That’s the whole problem. A made-up figure arrives in the same calm, helpful voice as a correct one, so you can’t tell them apart by tone. And tone is what most of us are quietly judging on.

So I stopped judging on tone. Before I act on anything an AI tells me about something that matters, I make it answer two questions first. The whole check takes under a minute. If you want it ready to go, paste this in before you trust its next answer:

// Paste this before you act on an AI answer

Before you answer anything else: name exactly what you’re looking at, the specific document or page in front of you. Then give me one fact about it I can check myself in under a minute. If you’re not sure what you’re looking at, say so before you go any further.

That’s the whole thing. Here’s why each half earns its place.

Question one: name the exact thing

This is the one I never skip. Take something ordinary. Say you’ve pasted in your phone contract and asked for a plain summary. Before you read a word of that summary, make the AI tell you what it’s looking at: which provider, which plan, the monthly price printed at the top. “Which provider is this, and what am I paying a month?”

This sounds too obvious to bother with. It isn’t. An AI that’s muddled about which thing you mean will cheerfully answer about a different one and never flag the swap, like a waiter who brings the wrong table’s order and reads it out to you with total confidence. If it says £29 when the page in front of you says £39, stop there. It’s describing someone else’s contract in a very reassuring voice.

Question two: one fact you can check in 30 seconds

I added this half later, once I’d noticed the first question alone wasn’t enough. Now make it hand you something you can verify yourself, fast: one date, one number, one name you can hold against the document. A made-up number gives itself away the second you check it. A right answer about the wrong thing never does: every fact is correct, neatly laid out, and about a contract you’ve never seen in your life.

Fail either, and bin the whole thing

Here’s the rule I’m strictest about with myself. Not the bad line. The lot. If it couldn’t tell you what it was looking at, nothing it said next was about your problem; it was a tidy, confident essay answering a question you never asked. The good-looking paragraphs are the part that nearly fooled you.

What it told you
Here's a plain summary of your phone contract. You're paying £29 a month, with the usual allowances and a standard minimum term.
What one fact catches
The page in front of you says £39, not £29. It's describing someone else's contract in a very reassuring voice. Fail the fact, bin the whole thing.

Two questions won’t catch all nine ways AI gets things wrong. They catch the expensive ones fastest, and the rest of the checks are on the Guardrails page.

It works the same on anything that matters: a contract summary, a letter from your doctor, a holiday booking, an email from your child’s school. Name the thing. Check one fact. Then decide whether to believe a word of it.

Next: the whole method, in four questions → The whole method, in four questions

Ben Dixon
// Written by Ben Dixon

Ben tests how far you can trust the main AI assistants, and publishes exactly where they get things wrong. Every post here is a first-hand test with the receipts, including the times a tool simply wasn’t worth the trust. About Ben →

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The site tests how far you can trust the main AI assistants, on real decisions. Start with the Prompt Stack for the four-stage framework, free and ungated, or the Bluff Filter for the paste-ready version with a real before and after.

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