Claim extraction
Last updated: July 26, 2026
Claim extraction is breaking an AI answer into atomic, individually checkable statements — one verifiable fact each. It is the first step of verification: you can't ground a whole paragraph at once, so you split it into claims that can each be tested against a source separately.
What is claim extraction?
Claim extraction is the step that turns a block of AI text into a list of atomic, checkable claims — each a single factual assertion you can test on its own. A sentence often contains several claims; extraction pulls them apart so none is checked jointly with another.
It matters because grounding operates on claims, not paragraphs. A paragraph can be 90% right with one buried falsehood; if you check it as a lump, the good drowns the bad. Extraction isolates each assertion so the one wrong claim gets its own verdict.
Good extraction is harder than it looks. It has to split compound sentences, resolve pronouns and references, and keep enough context that each claim stands alone and remains meaningful.
Why it's the first step of verification
Everything downstream depends on clean extraction. You ground a claim, you assign it a verdict, you roll verdicts into a risk score — all at the claim level. If extraction merges two claims, one verdict has to cover both, and precision suffers.
Extraction also decides what is even checkable. Opinions, instructions, and hedged statements aren't factual claims and shouldn't be grounded as if they were. Separating checkable claims from non-claims keeps the false-alarm rate down by not flagging things that were never assertions of fact. See how it works.
A worked example
Take the sentence: "Marie Curie, who won two Nobel Prizes, discovered penicillin in 1928." Extraction produces three claims:
- Marie Curie won two Nobel Prizes. → supported
- Penicillin was discovered in 1928. → supported
- Marie Curie discovered penicillin. → contradicted (it was Alexander Fleming)
Checked as one sentence, the true parts might mask the false one. Extracted, the false claim gets its own contradicted verdict and is surfaced cleanly. Try it on the verifier.
Frequently asked questions
What is an atomic claim?
An atomic claim is a single factual assertion that can be verified on its own — 'penicillin was discovered in 1928', not a whole sentence bundling several facts. Extraction aims for atomic claims so each gets its own verdict and no true statement hides a false one.
Does claim extraction check opinions?
No. Opinions, instructions, and hedged or subjective statements aren't factual claims, so extraction separates them out and doesn't ground them as facts. This keeps the false-alarm rate low by not flagging things that were never assertions of fact.
Why not just check the whole answer at once?
Because a paragraph can be mostly true with one buried falsehood. Checked as a lump, the falsehood gets averaged away. Extracting atomic claims isolates each assertion so the single wrong one gets its own contradicted verdict and is surfaced. See fact-checking.
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