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Base-size neglect

Interpreting a count or percentage without considering the total group it came from.

Published 04 August 2026Updated 04 August 2026

Base-size neglect makes a percentage or case count seem meaningful while its denominator remains hidden. Restore the total number of opportunities or people, then compare absolute counts, percentages, and relevant baselines together.

Sources

Judgment under Uncertainty: Heuristics and Biases

Science / 1974 / Paper

Classic heuristics and biases paper.