What is how to take smart notes?

How to take smart notes is a concept in personal epistemology: Taking notes while reading or listening forces active processing.

Example: You read a 4,000-word article on decision fatigue. Without notes, you finish it and retain a vague sense that 'decisions are tiring.' With notes, you pause after each section to write one sentence capturing the core claim in your own words: 'Baumeister's ego depletion model says self-control draws from a finite pool — but replication failures suggest beliefs about depletion may matter more than actual depletion.' That sentence required you to compare claims, resolve an ambiguity, and compress the argument into a structure you can reuse. The note is not a record of what you read. It is evidence that you processed it.

This concept is part of Phase 43 (Information Processing) in the How to Think curriculum, which builds the epistemic infrastructure for information processing.