  ‘Bayesianism’ is a general term for a range of sophisticated statistical methods, algorithms, and tools that draw upon Bayes’ Theorem/Rule, which tells us how to revise our beliefs given new information; that is, how to choose the best of a set of alternative hypotheses given new data. The calculation requires (i) the prior probability of the data, (ii) the probability of the data given the hypothesis, and (iii) the prior probability of the  hypothesis.[27]