Verification

Checking a claim against the document it came from, particularly where a machine produced the claim.

Here the rule that holds up is that every figure entering published analysis must be traceable to a primary document, and a number nobody can trace doesn't go in.

Language models fail in a specific and dangerous way here. Fabricated citations and misattributed figures look identical to correct ones, and so do confidently wrong dates. Fluency isn't evidence.

Verification costs minutes. An invented statute costs a reputation.