Meanings
alternative Bayes theorem · alternative Bayes's theorem
- mathematicsA theorem expressed as an equation that describes the conditional probability of an event or state given prior knowledge of another event.
Bayes's theorem is a relationship between the conditional probabilities of two events.
2011, Allen Downey, Think Stats, O'Reilly, page 562 more examples
The starting point for many techniques in probabilistic classification is Bayes' theorem, which provides a way of relating evidence to a hypothesis.
2010, Jonathan Harrington, Phonetic Analysis of Speech Corpora, page 327We have now seen how Bayes' theorem enables us to correctly update a prior probability for some unknown event when we see evidence about the event.
2013, Norman Fenton, Martin Neil, Risk Assessment and Decision Analysis with Bayesian Networks, Taylor & Francis (CRC Press), page 131Synonyms: Bayes' law, Bayes' rule
Synonyms & antonyms
proper nounA theorem expressed as an equation that describes the conditional probability of an event or state given prior knowledge of another event.
Origin
Named after English mathematician Thomas Bayes (1701–1761), who developed an early formulation. The modern expression of the theorem is due to Pierre-Simon Laplace, who extended Bayes's work but was apparently unaware of it.
Full word history & related roots →Cite this entry
Bayes' theorem. (n.d.). In WatkinsX Dictionary. Retrieved November 5, 2026, from https://dictionary.watkinsx.com/word/Bayes'%20theorem
“Bayes' theorem.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/Bayes'%20theorem. Accessed November 5, 2026.
WatkinsX Dictionary, s.v. “Bayes' theorem,” accessed November 5, 2026, https://dictionary.watkinsx.com/word/Bayes'%20theorem.
Source: Bayes' theorem on Wiktionary, CC BY-SA 4.0.