Fermi Estimation
Fermi Estimation is a technique for making order-of-magnitude estimates of unknown quantities using basic reasoning and widely-known reference points. Named after physicist Enrico Fermi, who could estimate complex quantities (like the number of piano tuners in Chicago) with surprising accuracy from first principles, it develops the skill of producing defensible approximations when exact data is unavailable β essential for decision-making under uncertainty.
Planning Fallacy
The Planning Fallacy is the tendency to underestimate the time, costs, and risks of future plans while overestimating their benefits, even when aware of past projects' tendency to run over. Described by Daniel Kahneman and Amos Tversky (1979), it is one of the most costly cognitive biases in project management, construction, software development, and government, and is best corrected using Reference Class Forecasting β anchoring estimates in the historical base rate of similar projects.