How to summarise long files

Why it helps

Officers regularly face long documents with little time: a 60-page report before a meeting, a thick file with years of correspondence, minutes of several meetings, a new policy document. Summarisation is one of the things AI does best. It can give you the main points in a few paragraphs, so you know where to focus your own reading.

A summary is a map, not the territory. It tells you where to look. It does not replace reading the parts that matter.

Before you start

• Check what you are allowed to share. Public documents, such as published reports, gazette notifications and policy papers, can usually go into any assistant. Internal, classified or personal material cannot go into a public chatbot. Use only tools your department has approved for official data.
• Know the limits of length. Every AI has a context window: a maximum amount of text it can consider at once. Very long documents may need to be summarised in parts.

Step by step

1. Tell it who you are and why you need the summary. "I am briefing a senior officer before a meeting on X" gives a far better result than "summarise this".
2. Ask for a specific shape. For example: five key points, decisions required, risks and any deadlines.
3. For long files, work in sections. Summarise each section, then ask for a summary of the summaries.
4. Ask for references. "For each point, give the page or paragraph number it comes from." This makes checking quick.
5. Check the important points against the original. Especially numbers, dates, names and anything you will repeat to others.

Example instructions

I need to brief a Joint Secretary in 10 minutes. Summarise this report in no more than 8 bullet points: the main findings, the recommendations, any costs mentioned and any deadlines. Give the page number for each point.

Here are the minutes of three meetings. List every decision taken, who was made responsible and the deadline, as a table with columns: decision, responsible, deadline, meeting date.

What does this document NOT say that a reader might assume it says? List any gaps or ambiguities.

Common mistakes

• Trusting a summary of a document the AI did not fully see. If the file was too long, the AI may have summarised only part of it without saying so. Ask: "Did you read the whole document? What was the last section?"
• Losing the conditions. Summaries often drop the "unless", "subject to" and "provided that" clauses that change meaning in official text. Check these yourself.
• Mixing up who said what. In correspondence and minutes, confirm that positions are attributed to the right person or department.

A good habit

When you use a summary in your own note, read the original passages behind the two or three points your note relies on. It takes five minutes and protects you from repeating an error under your own name.