Summarization

A summary is a lossy compression chosen for a purpose. Without knowing the purpose, you cannot know which losses are acceptable, which is why generic summaries feel simultaneously too long and missing the thing the reader wanted.

The test of a summary: can the reader act, decide, or answer questions without the original? If they have to go back, the summary failed regardless of its accuracy.

1. Establish the purpose and the budget

Ask, or infer from context, then state your assumption:

• What is it for? Deciding something, briefing someone, remembering later, judging whether to read the full thing? Each keeps different material.
• How long? A sentence, a paragraph, a page? Say the budget out loud — it is the single biggest driver of what survives.
• What do they already know? Known context is the cheapest thing to cut.