Ask a notebook question and check the cited passage
The answer has a citation, so it must be right. Then you open it and find it's quoting last year's expenses policy, which the notebook still contains.
What you'll make
a short answer to one question about your documents, with each citation opened and checked against the right document and version, and anything the sources don’t say marked as not stated.
What you'll need
a notebook in Gemini Notebook (the product formerly called NotebookLM) containing documents you’re allowed to use, one question you need answered, and about ten minutes.
Example result.
Q: Which expense claims need line-manager approval?
A: Claims over £250 need line-manager approval, unless the cost was
pre-approved in a travel request. (Expenses policy 2026, section 4.2)
Checked: citation opened; 2026 version; condition read in full.
Not stated: who approves claims when the line manager is away.1. Choose the sources the answer may use
In the Source panel on the left, select only the documents that should answer this question. If the notebook holds several versions of a policy, leave the old ones unselected. Choose sources for a notebook covers building the set in the first place.
Why this works: the notebook answers from whatever is selected. An old version left selected is a real, citable passage, which is what makes it dangerous.
What you should see: only the current, relevant documents selected.
2. Ask a question the sources can answer
Ask about one decision, and name the source if you can. Google suggests mentioning source names in your question to help the notebook narrow its search.
Using only [source name], answer [question]. Give the rule, its
conditions and any exceptions, with a citation for each. Keep the
source's wording separate from your interpretation. If the source
doesn't answer part of the question, say "not stated".[source name] is the document title as it appears in the Source panel; [question] is your one question.
Why this works: splitting rule, conditions and exceptions makes the answer easier to check than a smooth paragraph, and “not stated” gives gaps somewhere to go.
What you should see: a short answer with citations attached to each claim.
3. Open each citation and check both directions
Hover over a citation to see the quoted text, then select it to jump to the quote in its document. For each one:
- Right document, right version? Check the title and date at the top of the source, not only the sentence.
- Does the passage say what the answer says? Read the sentence before and after. Look for “only”, “unless”, “may” or “subject to”.
- What did the answer leave out? Now go the other way: read the passage and ask whether it contains a condition or exception the answer didn’t mention.
If a short source is cited as a whole rather than at a passage, open it and find the wording yourself.
Why this works: checking from answer to passage catches invented additions. Checking from passage to answer catches missing restrictions. You need both.
What you should see: every claim matched to a passage in the current version, with anything missing added or marked.
Check the result
- Every citation points to the current version of the document.
- Each claim says what its passage says, conditions included.
- Anything the sources don’t cover is marked “not stated”, not filled in.
- You’ve read the passage around each citation, not only the highlighted words.
The usual failure: the citation is real but the document is wrong. The notebook quotes a superseded version, a draft or a similar policy from another team, and the citation makes it look settled. Spot it by checking the title and date of every cited source before you read the sentence.
Your answer cites [old source] for [claim]. The current document is
[current source]. Answer again using only [current source], cite the
passage, and tell me if the two versions differ on this point.[old source] is the superseded document; [claim] is the claim it supported; [current source] is the document that should be used.
Worked example: two expenses policies in one notebook
Fictional example. Sam in the finance team keeps a notebook of HR and finance policies. It holds both the 2025 and 2026 expenses policies. Section 4.2 of each says:
Expenses policy 2025, s.4.2: Claims over £150 need line-manager approval.
Expenses policy 2026, s.4.2: Claims over £250 need line-manager approval,
unless the cost was pre-approved in a travel request.With every source selected, the question “Which expense claims need line-manager approval?” got: “Claims over £150 need line-manager approval [1].”
- The failure. Citation [1] opened at the 2025 policy. The sentence is accurately quoted; it’s just last year’s rule. It also misses the travel-request exception, which only exists in 2026.
- The repair. The repair prompt, naming both policies, gave the example result above and added: “The 2025 policy set the limit at £150 with no travel-request exception.” Sam then unselected the 2025 policy in the Source panel.
- Checking the other direction. Reading section 4.2 of the 2026 policy turned up nothing about who approves when a manager is away, so that went down as “not stated” rather than being guessed.
Task kit for this job: Download (ZIP) · Reusable instructions
Go deeper
Keep a small record of what you checked
For anything that will be acted on, note the claim, the document title and version, the section and what you checked. That’s four lines, and it lets the next person reuse your check instead of repeating it. Don’t paste a whole confidential document into a shared record unless that’s allowed.
Fix the notebook, not just the answer
If an old version keeps getting cited, remove it from the notebook or move it to a separate archive notebook. Unselecting it works for one chat; removing it works for everyone who uses the notebook. Refresh a notebook when the documents change covers this.
Ask for every passage on the topic
When a policy is long, ask for the material before the rule: “List every passage in [source name] about [topic], in document order, with its section. Don’t summarise.” Reading the list is slower and much harder to get wrong. The beginner’s guide to Gemini Notebook covers the rest of the product.