# Bayes' theorem

[ beyz, bey-ziz ]
/ beɪz, ˈbeɪ zɪz /
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noun Statistics.
a theorem describing how the conditional probability of each of a set of possible causes, given an observed outcome, can be computed from knowledge of the probability of each cause and of the conditional probability of the outcome, given each cause.
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## Origin ofBayes' theorem

see origin at Bayesian

## Words nearby Bayes' theorem

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

## British Dictionary definitions for Bayes' theorem

Bayes' theorem
/ (beɪz) /

noun
statistics the fundamental result which expresses the conditional probability P (E/A) of an event E given an event A as P (A/E). P (E) /P (A); more generally, where E n is one of a set of values E i which partition the sample space, P (E n /A) = P (A/E n) P (E n) / Σ P (A/E i) P (E i). This enables prior estimates of probability to be continually revised in the light of observations

## Word Origin for Bayes' theorem

C20: named after Thomas Bayes (1702–61), English mathematician and Presbyterian minister
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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