What is distinguishing signal from noise?

Distinguishing signal from noise is a concept in personal epistemology: Not every recurring event is meaningful — some repetitions are coincidental.

Example: You notice you've had three bad meetings on Tuesdays and conclude 'Tuesdays are my worst day.' But you've had 200 Tuesday meetings total — three bad ones is a 1.5% rate, no different from any other day. You detected a pattern, but the pattern was noise. A signal pattern would be: every meeting where you skipped your 10-minute prep routine went poorly, regardless of the day. One pattern is coincidence dressed as insight. The other is a structural cause you can act on.

This concept is part of Phase 6 (Pattern Recognition) in the How to Think curriculum, which builds the epistemic infrastructure for pattern recognition.