The base rate fallacy, also called base rate neglect or base rate bias, is an error that occurs when the conditional probability of some hypothesis H given some evidence E is assessed without taking into account the prior probability ("base rate") of H and the total probability of evidence E. The conditional probability can be expressed as P(H|E), the probability of H given E, and the base rate error happens when the values of sensitivity and specificity, which depend only on the test itself, are used in place of positive predictive value and negative predictive value, which depend on both the test and the baseline prevalence of event.
Read more about Base Rate Fallacy: Example, Mathematical Formalism, Findings in Psychology
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