Evidence Theory as a procedure for Handling Novel Events

Evidence Theory is a branch of the mathematics of uncertain reasoning that entails profound epistemological differences with respect to Probability Theory. In fact, its paradigmatic situation is the judge who must evaluate testimonies, rather than the gambler who must evaluates odds. Unlike a gambler, who faces a definite set of possibilities, a judge may be forced to change her evaluation because of novel possibilities suggested by unexpected testimonies. In this sense, Evidence Theory provides a formalisation of some among Shackle¡Çs intuitions. Whilst the details of the connections between Shackle's theory and Evidence Theory have been explored elsewhere, this article is devoted to a detailed explanation of the working of Evidence Theory. An example is discussed in detail and several domains of application are briefly sketched.