Dempster-Shafer theory
The Dempster-Shafer theory is a mathematical theory of evidence that was introduced in the late 1970s by Glenn Shafer.
It is a way of representing epistemic plausibilities. It developed from a sequence of works of Arthur Dempster, who was Shafer's advisor.
In this formalism the best representation of chance is a belief function rather than a Bayesian probability distribution. Probability values are assigned to sets of possibilities rather than single events: their appeal rests on the fact they naturally encode evidence in favor of propositions.
