The base-rate fallacy is the cognitive error of neglecting prior probability (the base rate) when evaluating conditional evidence, overweighting specific case information at the expense of population-level statistics. Parameters: (1) base rate — the prior frequency of a property in the relevant population; (2) diagnostic evidence — a test, signal, or specific case detail with known sensitivity and specificity; (3) inversion — the fallacy occurs when P(h|e) is estimated without Bayes' theorem, equating P(e|h) with P(h|e). Persistence mechanism: mathematical education, statistical literacy programs, and the formal teaching of Bayesian reasoning in professional domains (medicine, law, finance). The concept persists through curriculum design and decision-support tools that force explicit prior consideration. [formal: fallacia rationis base | substrate: mind | horizon: a life | explicit: yes | epoch: 0.44]
Accepted ontology entry
base-rate-fallacy
The base-rate fallacy is the cognitive error of neglecting prior probability (the base rate) when evaluating conditional evidence, overweighting specific case information at the expense of population-level statistics. Parameters: (1) base…
Definition
Why it is in scope
a human-made cognitive concept describing the systematic error where people disregard general statistical frequencies in favor of case-specific information; built to persist through psychology curricula, decision-science literature, and behavioral-economics teaching
Names and aliases
- base-rate-fallacyen · CANONICAL
Relations from this entry
- cmrmwufxy01pxd1nllvxs1o1sINSTANCE_OF →
base-rate-fallacy is a specific type of cognitive bias — the error of ignoring prior probabilities in favor of specific case information. Clear specific→general. Law 9: the specific points at the general, never the reverse.
- cmrn2b9bk01v9d1nlws1gj4eaINSTANCE_OF →
Base rate fallacy IS a specific kind of fallacy — the error of ignoring prior probabilities in favor of individuating information. A competent speaker would call it a fallacy. Nearest kind: fallacy.
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No accepted relations in this direction.
Record identity
- Created
- Jul 18, 2026, 9:57 AM UTC
- Content hash
- 284e2252f5df676deb78f2cbe99881e3b15daf680fdd949309b195fee420337e