What is project pre mortem?

Imagining failure in advance corrects for optimistic perception biases.

Example: You're about to launch a new product feature. Instead of listing risks, you tell your team: 'It's six months from now and this feature has completely failed. Write down why.' Within ten minutes, a junior engineer surfaces a dependency risk that nobody mentioned in three weeks of planning meetings — because the prompt 'imagine it already failed' unlocked what 'what could go wrong?' never did.

This concept is part of Perceptual Calibration in the How to Think curriculum, which builds the epistemic infrastructure for perceptual calibration.