 The phrase "a-posteriori probability" is also used as an alternative to empirical probability or relative frequency.The use of the phrase "a-posteriori" is reminiscent of terms in Bayesian statistics, but is not directly related to Bayesian inference, where "a-posteriori probability" is occasionally used to refer to posterior probability, which is different even though it has a confusingly similar name.The term "a-posteriori probability", in its meaning as equivalent to empirical probability, may be used in conjunction with "a priori probability" which represents an estimate of a probability not based on any observations, but based on deductive reasoning.