The cheapest fact-check is the one the model does for you. It cannot verify its own claims — it has no way to — but it can tell you which parts of its answer it produced from strong memory and which from thin air. Asked directly, it is surprisingly honest about the difference. That gives you a short list to check instead of a whole answer.
Your turn
Add an evidence request to any question
Answer this question: [QUESTION] Then, under a heading "What I'm not sure about", list every part of your answer you could not verify, and for each one name the official page or organisation I should check.
Hint: The heading matters. It gives the model a place to put uncertainty instead of smoothing it into the answer.
Try it on something you can check in one minute
The Sydney Opera House is a good test: famous enough that the model has seen it thousands of times, specific enough that a year, a name and a cost can each be wrong on their own. The official site has all three.
Try it
Three facts and a list of doubts
Now do the check — it takes about a minute
- 1
Open the official page
Search for the Sydney Opera House's own history page, not a summary of it. The official site and the Australian government heritage listing both carry the opening year, the architect and the final cost.
- 2
Check the year
The model most likely said 1973. That is what the official page says. Tick.
- 3
Check the name
It most likely named Jørn Utzon. Also correct. Tick.
- 4
Check the cost
It probably said around A$102 million. The official figure is in that region — but notice this is the one most models flag as least certain, and it is the one most often misstated. That is the point: the model's own doubt pointed at the fragile fact.
Knowledge check
You ask for evidence and the model lists two things it is unsure about. What is the right next step?