Lesson 5 · Beginner · 15 min
Checking an answer: sources, figures, dates
Three checks before using a Copilot Chat answer: open the cited sources, cross-check every figure, date every piece of information.
- Goal
- You will be able to decide in five minutes whether a Copilot Chat answer is usable: source opened, figure cross-checked, date known.
- Skills
- Check
Your first attempt, unaided
Ask Copilot Chat for a recent figure from your sector, with its source. Then take five minutes to open the link provided and find that exact figure in the page. Note how long it took you.
Before using an answer, make three checks. Open every cited source and make sure it really says what the answer claims. Cross-check every figure against the original page or document, unit and period included. Date every piece of information, because a rule from 2019 is not necessarily still true in 2026. A statement without an opened source remains a hypothesis, however confident the tone.
1Why a fluent answer can still be wrong
When Copilot Chat uses web search, the answer arrives with clickable citations. According to Microsoft's documentation, the generated web queries are shown in the citations section and stay visible in the conversation for 24 hours. A citation is a starting point, not a verdict: it proves that a page was consulted, not that the page says what the answer claims, nor that the page is reliable.
The first check concerns the source. Does the page still exist? Does it contain the statement, or only a related topic? Who published it: an official site, a professional body, a blog, a forum? The second check concerns the figure: same value, same unit, same period. A model can round, mix up two financial years or pick up a figure from another page. The third check concerns the date: the page's publication date, the rule's validity date, and what the answer never says, the date at which the model stopped learning.
When no citation appears, there are two explanations: the model judged that a search was not needed, or your administrator switched web search off, in which case Copilot Chat uses the model alone. In both cases the answer comes from training. Ask for a source, or provide the document.
Checking is prepared in the prompt. Impose the type of source, demand the link and the publication date, separate "what the text says" from "interpretation", plan the exit "if you cannot find it, say so". The "Cite sources and flag uncertainty" booster adds these instructions in one tick box. But the last check remains yours: a model proofreads its own answers poorly, and it cannot open a link for you.
Check The question to ask Warning sign Source Does the page exist and does it say that? No link, dead link, forum, page without an author Figure Same value, same unit, same period? Round figure, no unit, no year Date How old is the page, is the rule in force? Page over two years old on a regulatory topic 
Diagram "Check an answer before using it"Diagram generated by AI and reviewed 2A public procurement threshold, checked step by step
A buyer is preparing a tender and wants to know the threshold below which a public contract can be awarded without advertising or competitive bidding.
Weak prompt.
What is the threshold below which a public contract can be awarded without a procedure?Copilot gives an amount, with or without a citation. That threshold has been changed several times in recent years and the answer does not say which year it applies to.
Strong prompt.
Search the web for the procedure-exemption threshold for public contracts in France, in force on 1 September 2026. Use only official sources: legifrance.gouv.fr, economie.gouv.fr or service-public.fr. Give the amount excluding VAT, the reference text, the exact link to the page you consulted and its publication date. Separate "what the text says" from "interpretation". If sources contradict each other, present both; if you cannot find an official source, say so.The answer gives an amount, a reference article, an official link and a page date. You open the link, find the amount on the page, note its date. Verdict in two minutes.
What changes.
- The validity date is in the question: the model no longer mixes up years.
- The type of source is imposed: no blog, no forum.
- The link and the page date make your check possible and fast.
3Check three statements in one answer
Take a regulatory topic from your job: mandatory notices, invoicing, data protection, safety. Here is the starting prompt, to be improved:
"What are the new obligations for companies in 2026?"
Name the topic and the validity date, impose official sources, demand the link and the publication date for every statement, plan for the case where no official source exists. The composer below helps you. Run it, then apply the three checks to the answer: open two links, cross-check one figure, note the dates. Write your verdict for each statement: confirmed, refuted or unverifiable.
Self-assessment grid: (a) every statement has a link; (b) two opened links confirm the content; (c) at least one item was marked unverifiable or refuted, with the reason.
4The link that exists but says something else
A manager asks for the average absenteeism rate in his sector. Copilot answers "5.6% in 2025" with a link to the website of a well-known organisation. The link opens, the site is credible, and the figure goes straight into a presentation. What he should have seen: the cited page exists, but it contains neither "5.6%" nor the year 2025; it gives an all-sector rate for 2023. A citation proves that the page exists, not that the sentence is on it. A 2023 academic study measured that generative search engines fully supported only about one sentence in two with their citations. Correction: "For every figure, quote the exact passage of the page that contains it, with the year it refers to. If you cannot quote the passage, write "unverified" instead of the figure." Then open the page and search for the passage with Ctrl+F: if it is not there, the figure has no source. Rule to remember: opening the link is not enough, you have to find the sentence.
5Quiz
Three questions, instant feedback. Each option comes with an explanation.
6Proof of mastery
Paste a Copilot Chat answer containing at least one figure and one date, your checking prompt, then your verdict: for each item, the source opened, confirmed or refuted.
Criteria
What you wrote at the start of the lesson
Going further
The lesson How a generative AI answers explains why an invented figure looks just like an exact one. The next lesson, Before you paste a text, deals with what must stay out of the conversation. The glossary defines hallucination and grounding. The Copilot prompts for buyers sheet applies these three checks to tenders and supplier quotes.
Frequently asked questions
Is an answer with citations necessarily right?
No. A citation proves that a page was consulted. It guarantees neither that the page says what the answer claims, nor that the page is reliable or up to date. Open it: that is the only check that counts.
Why does my answer have no citation at all?
Either the model judged that a search was not needed, or your administrator switched web search off, in which case Copilot Chat uses the model alone. In both cases the answer comes from training: ask for a source, or provide the document.
How long do citations stay visible?
According to Microsoft, the generated web queries are shown in the citations section and kept in the conversation for 24 hours. Copy the links you need into your note at the time you check.