adj. denoting an approach to statistical inference and probability that enables previously known (a priori) information about a population characteristic of interest to be incorporated into the analysis. In Bayesian methods, estimated quantities are based in part on empirical data (i.e., what was actually observed) and in part on collective or individual knowledge about what to expect in the population (as captured in a prior distribution). See also posterior distribution. [Thomas Bayes (1702–1761), British mathematician and theologian]