What is five whys root cause analysis?

Five whys root cause analysis is a concept in personal epistemology: Asking why five times in succession usually reaches the root cause of a problem.

Example: Your weekly planning session keeps running over ninety minutes, leaving you frustrated and behind schedule. You could shorten the agenda or set a harder stop time — both are symptom fixes. Instead, you ask why. Why does the session run long? Because you spend too much time on task prioritization. Why? Because you arrive at the session without a pre-ranked list. Why? Because you never review your backlog before the session. Why? Because you treat the planning session as the place where prioritization happens, rather than where prioritized decisions get confirmed. Why? Because you never separated the act of evaluating tasks from the act of scheduling them. The root cause is a missing upstream step — a five-minute backlog review the night before — not a time management problem at all.

This concept is part of Phase 25 (Error Correction) in the How to Think curriculum, which builds the epistemic infrastructure for error correction.