Browse Teach Curate

The Planning Fallacy in Project Estimation

Describes the well-documented tendency for people to underestimate the time, cost, and risk of future tasks even when they know similar past tasks ran long. Distinguishes the fallacy from simple bad luck by showing it holds even for experienced planners with full information available to them. Used to justify estimation techniques that pull in outside data rather than trusting an inside, case-by-case forecast.

Chief Galen Tyrol Video

The Planning Fallacy in Software Estimates, via Kahneman's Textbook Story

Uses Kahneman's own textbook-writing anecdote to show why experienced planners still underestimate duration, and argues for outside-view estimation techniques.