As was explained above, there is controversy in regard to the proper meaning and interpretation of some of the probabilities that are assigned to the outcomes of many experiments. However, once probabilities have been assigned to some simple outcomes in an experiment, there is complete agreement among all authorities that the mathematical theory of probability provided the appropriate methodology for further study of these probabilities. Almost all work in the mathematical theory have been related to the following two problems:(a). methods for determining the probabilities of certain events from the specified probabilities of each possible outcome of an experiment and;(b). methods for revising the probabilities of events when additional information is obtained.