Most Probable Explanation

Overview

The Most Probable Explanation (MPE), also called the Maximum A Posteriori (MAP) assignment, corresponds to the fully instantiated particle that has the highest probability. If we think about the Joint Probability Distribution as a hypercube, the MPE is the cell with the highest probability.

Because the MPE returns a fully instantiated particle, every node is instantiated, so all dimensions of the domain carry the same weight. Adding irrelevant or redundant dimensions can therefore affect the result. The MPE is sometimes counter-intuitive, as it does not necessarily correspond to the marginally most likely state of each node.