# A priori probability

From Encyclopedia of Mathematics

*of an event*

The probability of the event, considered in contrast to the conditional probability of the same event under certain additional conditions. The latter is called the a posteriori probability. This terminology is, as a rule, used in connection with the Bayes formula.

**How to Cite This Entry:**

A priori probability. Yu.V. Prokhorov (originator),

*Encyclopedia of Mathematics.*URL: http://www.encyclopediaofmath.org/index.php?title=A_priori_probability&oldid=17745

This text originally appeared in Encyclopedia of Mathematics - ISBN 1402006098