On Rho in a decision-theoretical apparatus of Dempster-Shafer theory

Authors:

  • Schubert Johan

Publish date: 1993-06-14

Report number: FOA C 20927-2.7

Pages: 12

Written in: English

Abstract

Thomas M. Strat has developed a decision-theoretic apparatus for Dempster-Shafer theory (Decision analysis using belief functions, Int. J. Approx. Reasoning 4(5/6), 391-417, 1990). In this apparatus, expected utility intervals are constructed for different choices. The choice with the highest expected utility is preferable to others. However, to find the preferred choice when the expected utility interval of one choice is included in that of another, it is necessary to interpolate a discerning point in the intervals. This is done by the parameter p, where p is defined as the probability that the ambiguity about the utility of every non-singleton focal element will turn out as favorable as possible. In Strats apparatus, an assumption, unwarranted by the evidence at hand, has to be made about tha value of p. In this article we demonstrate that no such assumption is necessary. It is sufficient to assume a uniform probability distribution for p to be able to discern the most preferable choice. We will discuss when this approach is justifiable. the utility of every non-singleton focal element will turn out as favorable as possible. In Strats apparatus, an assumption, unwarranted by the evidence at hand, has to be made about the value of p. In this article we demostrate that no such assumption i s necessary. It is sufficient to assume a uniform probability distribution for p to be able to discern the most preferable choice. We will discuss when this approach is justifiable.