USING BELIEF FUNCTIONS TO REPRESENT DEGREES OF BELIEF

Belief functions are an alternative or supplement to probabilities for representing the degree to which we believe in various hypotheses, hi ghlighting different aspects of subjects' uses of evidence. In particu lar, belief functions have potential for situations in which the belie f assessor is interested in judging the degree of support or justifica tion that the evidence affords hypotheses, e.g., in legal situations. Noting that there is a lack of empirical evidence testing the theoreti cal claims in favor of using belief functions, we constructed an exper iment to determine (a) if subjects could be trained in the meanings of belief-function responses; and, (b) once trained, how they use those belief functions in a hypothetical legal setting. We found that subjec ts could use belief functions, identified limits to belief functions' descriptive representativeness, and discovered patterns in subjects' u ses of belief functions that inform our understanding of subjects' use s of evidence. (C) 1994 Academic Press, Inc.