Faithful Approximations of Belief Functions

A conceptual foundation for approximation of belief functions is proposed and investigated. It is based on the requirements of consistency and closeness. An optimal approximation is studied. Unfortunately, the computation of the optimal approximation turns out to be intractable. Hence, various heuristic methods are proposed and experimantally evaluated both in terms of their accuracy and in terms of the speed of computation. These methods are compared to the earlier proposed approximations of belief functions.