Specifying nonspecific evidence
Publish date: 1994-05-17
Report number: FOA C 20975-2.7
Pages: 29
Written in: English
Abstract
In an earlier article (J. Schubert, "On nonspecific evidence," Int. J. Intell. Syst. 8(6), 711-725 (1993)) we established within Dempster-Shafer theory a criterion function called the metaconflict function. With this criterion we can partition into subsets a set of evidences with propositions that are weakly specified in the sense that it may be uncertain to which event a proposition is referring. Each subset in the partitioning is representing a separate event. The metaconflict function was derived as the plausibility that the partitioning is correct when viewing the conflict in Dempster´s rule within each subset as a newly constructed metalevel evidence with a proposition giving support against the entire partitioning. In this article we extend the results of the previous article. We will not only find the most plausible subset for each piece of evidence as was done in the earlier article. In addition we will specify each nonspecific evidence by finding the plausibility for every subset that the evidence belongs to the subset. In doing this we will automatically receive an indication on how likely it is that this evidence is actually false. We will then develop a new methodology to exploit these newly specified evidences in a subsequent reasoning process. This will include methods to discount evidences based on their degree of falsity and on their degree of credibility due to a partial specification of affiliation, as well as refined method to infer the event of each subset.