How to fact-check AI-generated text claim by claim

Mark every claim before opening a browser

Read the draft once without rewriting it. Underline names, dates, quantities, quotations, rankings, causal statements, definitions, product capabilities, and claims about what a source says. Mark broad claims too: words such as ‘most’, ‘first’, ‘proven’, and ‘always’ turn an ordinary sentence into something that needs unusually strong evidence.

Give each marked sentence a status: known from your own supplied source, needs verification, or opinion. This inventory matters because a general instruction to ‘check the facts’ encourages skimming. A list of eighteen claims can be cleared one by one and leaves visible evidence of what remains open.

Add a risk label while you mark claims. A low-risk claim is stable and easy to correct. A medium-risk claim could mislead the reader or damage the argument. A high-risk claim affects health, law, money, safety, reputation, or a person's words. Clear the high-risk group first and ask a qualified reviewer to inspect claims outside your expertise. This order prevents easy checks from consuming the time needed for consequential ones.

Trace the claim to the nearest primary source

Search for the underlying record using the same discipline as citation management, rather than a page that repeats the claim. For a law, open the statute or regulator. For research, open the paper and its methods, not a press release about it. For a product, use current official documentation. For a quotation, find the transcript, recording, or original publication.

Secondary reporting is useful for discovering a source and understanding context. It should not become the end of the trail when the primary material is available. If only secondary evidence exists, attribute the claim to that reporting and avoid presenting its interpretation as settled fact.

Use a source ladder when the ideal record is hard to reach. Start with the original document, dataset, recording, or official manual. If it is unavailable, look for a complete reproduction from a responsible archive, then independent reporting that identifies what it inspected. Record the missing primary source in the log. The weaker the source, the narrower and more clearly attributed the published wording should become.

A citation is not proof that the sentence is true; it is an address where you can perform the check.

Check entailment, not just matching words

A source can contain the same terms as a sentence without supporting the sentence. Read enough around the passage to answer four questions: does it say this, about this population, in this period, with this degree of certainty? A study of twelve volunteers cannot carry a claim about all writers, and an association cannot silently become a cause.

Record the exact page, table, section, or timestamp. Then write a one-line note explaining what the source permits you to say. If that line is narrower than the draft, narrow the draft. This is the point where honest verification improves the writing rather than merely decorating it with links.

Try to disprove the draft sentence before approving it. Search the source for exceptions, sample limits, later corrections, and definitions that differ from ordinary usage. Then write the strongest reasonable alternative explanation. If the evidence survives that test, the claim is sturdier. If it does not, the sentence may still be usable as an observation or attributed view, but it should not appear as an established conclusion.

Handle numbers, quotations, and changing facts separately

Recalculate simple percentages and totals from the underlying figures. Check that denominators, currencies, units, and date ranges match. Compare every quotation character by character and mark any omitted words. For facts that change - Prices, officeholders, software features, policies - Record the date on which you checked them and prefer wording that makes the time boundary visible.

Never repair a doubtful quotation from memory or ask another model to confirm it. Either locate the exact words, convert the idea into an attributed paraphrase, or remove it. A clean deletion is better than a vivid line that cannot survive a reader clicking the source.

For a number, preserve the calculation beside the draft: original figures, formula, unit, rounding choice, and source date. For a quotation, keep the full surrounding exchange and note whether punctuation or capitalization changed. For a current fact, assign an owner and a review date. These small records let another editor repeat the check instead of trusting a green tick whose reasoning has disappeared.

Keep a verification log

A compact log needs four columns: claim, source and locator, result, and action taken. It belongs beside the wider AI editing checklist. ‘Verified’ means the source supports the wording. ‘Revised’ means the source supports a narrower version. ‘Removed’ means no adequate support was found. ‘Pending’ means the piece is not ready to publish.

The log is useful beyond compliance. An editor can review the risky claims first, a future update can revisit facts that age quickly, and you do not have to repeat the entire search when the same evidence appears in another chapter. Keep it with the project, not in a temporary browser session.

A useful log entry is specific enough to reproduce: Claim C14; annual report, page 37, table 6; partly supported; changed 'all customers' to 'surveyed enterprise customers'; checked 2 November 2026. That one row shows the sentence, the exact evidence, the decision, and its time boundary. A row that says only 'looks right' records confidence, not verification.

Run a final contradiction and link pass

After individual claims clear, read the piece for contradictions between sections. Models often produce locally plausible passages that disagree about a date, a definition, or a recommendation. Search repeated names and numbers, then compare every occurrence.

Open every public link in a private window. Confirm it reaches the intended source without your account, points to the cited version, and preserves enough context for a reader to judge the claim. Only then remove the check markers and let the prose move to copy editing.

Finish by searching for the old wording. A corrected claim may survive in the title, caption, summary, chart label, alt text, metadata, or conclusion even after the body changes. Also compare the direct answer with the detailed sections. Readers and search systems often encounter those short elements first, so they must not repeat a stronger claim than the evidence supports.