Citations, Grounding and Uploaded Documents

Grounding means giving Claude material to answer from, rather than asking it to answer from memory. It is the most effective single technique for reducing fabricated content, and the Claude apps offer several ways to do it: attaching files to a chat, storing documents in a Project, enabling web search, and running Research. Each produces answers that point back to a source, and knowing how to read those pointers is a core exam skill.

Why grounded answers are more trustworthy

When Claude answers from its training data, you have no way to know which parts are reliable. When it answers from a document you supplied, you can check the answer against the document. The quality of the answer becomes a function of the quality of your source, which is under your control. Grounding does not make Claude infallible, since it can still misread a passage or combine two sections incorrectly, but it converts an unverifiable claim into a verifiable one.

Attaching files to a conversation

You can upload PDFs, Word documents, spreadsheets, text files and images directly into a chat. Claude reads the content (including text in images and scanned pages where legible) and can quote, summarise and analyse it. Points to remember:

• Files attached to a chat belong to that chat. A new conversation starts without them.
• There are limits on file size and on the number of files per conversation; these change over time, so check the current figures at support.claude.com rather than memorising them.
• Very long documents may exceed what Claude can hold at once. If a summary seems to cover only the first half, that is the reason; split the document or use a Project.
• Tell Claude how to use the file: "Answer only from the attached policy and quote the relevant section" is far stronger than attaching it silently.

Project knowledge

Projects (covered fully in Domain 4) let you store documents once and reuse them across many chats. When you ask a question inside a Project, Claude draws on the project knowledge. For small collections, everything is in view at once. For larger collections, the app switches to a retrieval approach: it searches the knowledge for the passages most relevant to your question and reads those. Retrieval is powerful but means Claude might miss a relevant passage if your question is phrased very differently from the source text. Asking "search the project knowledge for anything about termination notice periods" is more reliable than assuming it has already read everything.

Web search and Research

Web search lets Claude look things up live and return answers with links. Research goes further: it plans a multi-step investigation, runs many searches (and, where connected, searches your workplace tools), and produces a longer report with citations. Both are grounding tools. The report's claims are tied to sources you can open, which is exactly what you want for verification.

Two cautions. First, a web source can itself be wrong, biased or out of date; a citation tells you where a claim came from, not that it is true. Second, Research is best at breadth and synthesis; for a single precise fact, a targeted search plus a visit to the primary source is faster and more reliable.

Reading citations

In the Claude apps, grounded answers typically show numbered markers, footnotes or links to the source. Good habits:

• Click or open at least a sample of citations and confirm the source actually says what Claude says it does. Occasionally the source is real but the paraphrase overreaches.
• Note the type of source. A regulator's own page outranks a blog post summarising it.
• Check the date. Grounding in a 2021 article about a policy that changed in 2024 produces a confidently outdated answer.
• Watch for claims without a marker in an otherwise cited answer. Those are the ones Claude is supplying from memory.

Before and after

What is our notice period for senior staff?

Without grounding, Claude will describe typical notice periods and may present a plausible figure as if it were yours. Grounded:

Using only the attached Employee Handbook, what is the notice period
for staff at grade 6 and above? Quote the exact clause and give the
section number. If the handbook does not say, tell me that.

The answer will quote the clause, and you can find it in seconds.

Checklist for grounded work

• Have I supplied the source, or enabled search, rather than relying on memory?
• Have I told Claude to answer only from the source and to say when the source is silent?
• Have I asked for quotes or section references so I can locate the passage?
• Have I opened a sample of citations and confirmed they support the claim?
• Have I checked the date and authority of each source?

Exam focus

• Grounding turns unverifiable claims into verifiable ones by tying answers to supplied documents or live sources; it reduces but does not eliminate error.
• Files attached to a chat are scoped to that chat; Project knowledge persists across chats and may use retrieval for large collections.
• Web search and Research return sources you can open; a citation shows origin, not truth, so check authority and date.
• Instruct Claude to answer only from the source, quote the passage and state when the source is silent.
• Uncited sentences in an otherwise cited answer are the ones most likely to come from memory.