How do I fact check AI answers?

Run the five checks in order. Write the claim in one sentence, ask which source supports it, open that source yourself, and read the part that is meant to back the claim. If any step fails, the answer is a lead, not evidence.

The reason this matters is that AI answers arrive in the register of finished work: clean paragraphs, confident phrasing, no visible hesitation. A Microsoft Research survey of knowledge workers found that the more people trusted generative AI, the less critical thinking effort they reported, and the more their checking shrank to reviewing whatever the tool produced. Trust tends to arrive before verification does.

The five checks are deliberately boring. They are the ones a magazine fact checker runs: name the claim, name the source, open the source, compare. Writing them out matters, because the failure is rarely a decision to trust something wrong. It is that no decision is ever noticed.

Does the cited source actually exist and support the claim?

Open the link. A citation is a claim about a source, not the source itself. Find the specific passage that is supposed to support the sentence, and check whether it says that thing, something adjacent, or nothing at all.

Models produce references in the shape of references, and studies of AI search tools through 2025 kept finding that a meaningful share of generated answers contained errors, or citations that did not hold up when someone opened them. The tell is usually soft: the link resolves to a homepage, a press release, or a summary of a summary rather than the study itself.

The Stanford Encyclopedia of Philosophy treats critical thinking as evaluating a claim together with the reasons offered for it, which is the whole move here. Common Sense Education's guidance on evaluating information online says something similar to students: trace the claim back to the source that produced it, then judge the source itself. Neither half is optional when the answer is about to shape your work.

How can you check numbers, quotes, and dates quickly?

Search the exact number or phrase in quotation marks and see what comes back. If the only pages carrying it are AI-written summaries, the number has no retrievable origin. Check dates against the document the answer names, since time references are a common place for plausible drift.

Numbers are the fastest test because they are checkable. A figure that appears in one blog post and nowhere else, with no study, dataset, or filing behind it, is a placeholder wearing a statistic's clothes. Quotes work the same way: put the exact wording in a search box. If nothing surfaces, the quote is most likely a plausible reconstruction.

Dates deserve their own pass because they are quietly load-bearing. Whether a study is from 2019 or 2024 changes what it says about the world. A model that is unsure of a date will often supply one anyway, formatted correctly, which is exactly what makes it hard to notice.

What signs suggest the answer is filling a gap with confidence?

Watch for specific detail with no traceable source: a study name, a section number, a precise percentage. Watch for confidence that grows when you ask it to confirm. Language models generate likely continuations, so where the source material runs out, gaps get filled with plausible text rather than blank space.

Confident tone is style, not evidence, and it is the hardest signal to override, because it matches how we expect expertise to sound. A person who is unsure says so. A model usually keeps the tone steady and moves on, which is why the check has to be structural: source or no source, openable or not.

One useful habit is to ask, in a fresh message, what would have to be true for the answer to be wrong, and what evidence would change it. The reply proves nothing, but it shows you where the answer is thin, and thin places are where you go read the original.

When should you find a primary source instead?

Find the primary source whenever the claim would change what you do. Medical, legal, and financial questions, contract terms, safety guidance, and anything you plan to repeat to a colleague or a client belong in that group. Read the actual paper, filing, standard, or document.

The OECD's Digital Education Outlook tracks how quickly AI tools are moving into learning and work, which makes verification a practical habit rather than a research one. Nothing in that shift retires the older rule: the closer a claim sits to a decision, the less acceptable a summary becomes.

The shallowing hypothesis is the background here. Reading on screens, in feeds, and through summaries trains the fast pass: scan, extract, move on. Verification is the opposite motion, slow and deliberate, and it is what keeps you as the person doing the understanding rather than the person receiving its output.

How do you use AI without outsourcing your judgment?

Use it to generate questions, not verdicts. Before you read the model's summary, write your own one-sentence version. If the two disagree, open the source. Forming an answer before you see one is retrieval practice in the research sense, and it is the same act that makes comprehension stick.

Committing to your own answer first is also how you notice what you actually absorbed. It is the loop Absorb is built around: read a passage, answer for yourself, then see what you missed, with the app listed at https://apps.apple.com/us/app/absorb-comprehension-games/id6761365856 if you want to run that loop on your phone. The aim is not to distrust AI. It is to keep the judging part of your reading where it belongs.