When applying Bayes rule this is the probability one would assign to various parameters *before* considering additional evidence. It is then combined with the evidence from the data to obtain the posterior probability. In Bayesian statistics, the values for this prior may not be a true probability but rather prior belief encoded as probability.

Defined on page 70

Used on pages 69, 70, 71, 72, 74, 76, 77, 78, 80, 81, 85, 95, 97, 98, 101, 142

Also known as prior, prior probabilities, prior probability, prior probability distribution, priors