Learn / Glossary

Small-sample reasoning

Treating a small number of observations as more stable or representative than it is.

Published 04 August 2026Updated 04 August 2026

Small-sample reasoning overestimates what a limited sample can show and underestimates ordinary random variation. More observations help only when the sample is also drawn in a way that represents the target population.

Sources

Judgment under Uncertainty: Heuristics and Biases

Science / 1974 / Paper

Classic heuristics and biases paper.