Bayes' theorem

[ beyz, bey-ziz ]

/ beɪz, ˈbeɪ zɪz /

Save This Word!

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.

QUIZ

ARE YOU A TRUE BLUE CHAMPION OF THESE "BLUE" SYNONYMS?

We could talk until we're blue in the face about this quiz on words for the color "blue," but we think you should take the quiz and find out if you're a whiz at these colorful terms.

Question 1 of 8

Which of the following words describes “sky blue”?

navy

beryl

azure

TAKE THE QUIZ TO FIND OUT

Meet Grammar Coach

Write or paste your essay, email, or story into Grammar Coach and get grammar help

Improve Your Writing

Meet Grammar CoachImprove Your Writing

Origin of Bayes' theorem

see origin at Bayesian

Words nearby Bayes' theorem

bayberry, Bay City, Bayelsa, Bayern, Bayesian, Bayes' theorem, Bayeux, Bayeux tapestry, Bayezid II, bay-head bar, bay ice

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021

How to use Bayes' theorem in a sentence

The two wacky candidates combined for just over 5% of the vote with Brown pulling 3.3% and Bayes at 1.8%.
Who Voted For Idaho's Weirdo Candidates For Governor?|Ben Jacobs|May 21, 2014|DAILY BEAST
Obviously, these weren't the results that either Brown or Bayes were hoping for.
Who Voted For Idaho's Weirdo Candidates For Governor?|Ben Jacobs|May 21, 2014|DAILY BEAST
Two fringe candidates, Walt Bayes and Harley Brown were included and their participation made the debate go viral on the Internet.
Idaho’s Freakshow Debate|Ben Jacobs|May 16, 2014|DAILY BEAST
Bayes read Bible verses on stage and linked the 1986 nuclear disaster at Chernobyl to the Book of Revelations.
Idaho’s Freakshow Debate|Ben Jacobs|May 16, 2014|DAILY BEAST

Infinite Monkey Theorem has also landed praise in national publications including Wine Spectator as recently as last year.
Taste Off: Super Bowl State Wines From Colorado and Washington|Jordan Salcito|February 1, 2014|DAILY BEAST
This, however, is not a question of the method of the social science, but a theorem of the science itself.
A System of Logic: Ratiocinative and Inductive|John Stuart Mill
This was M. Comte's opinion; but it is by no means implied in his fundamental theorem.
A System of Logic: Ratiocinative and Inductive|John Stuart Mill
A modern historian aptly remarks that the medicine of the present "embraces nothing but a theorem of investigation by the senses."
An Epitome of the History of Medicine|Roswell Park
But as it seems not yet to have been stated clearly enough, I will here try to put my entire theorem into an unmistakable form.
The Stones of Venice, Volume III (of 3)|John Ruskin
But in the proof of this great theorem two influences were neglected, either of which is fatal to its validity.
A Text-Book of Astronomy|George C. Comstock

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