The Combination of Di erent Pieces of Evidence Using Incidence Calculus

Combiningmultiple sources of information is a major and di cult task in the management of uncertainty Dempster s combination rule is one of the attractive approaches However many researchers have pointed out that the application domains of the rule are rather limited and it sometimes gives unexpected results In this paper we have further explored the nature of combination and achieved the following main results The condition of combination in Dempster s original combination framework is more strict than that required by Dempster s combination rule in Dempster Shafer theory of evidence Some counterintuitive results of using Dempster s combination rule shown in some papers are caused by the overlooking or ignorance of di erent independence conditions required by Dempster s original combi nation framework and Dempster s combination rule In Dempster s combination rule combinations are performed at the target information level This rule itself does not provide a combination mechanism at the original information level so that it is not able to combine the overlapped information An alternative approach to the combination of di erent pieces of evidence by using incidence calculus is proposed In this approach di erent pieces of evidence are combined at both the original information level and the target information level rather than only at the target information level In this approach we can combine not only independent pieces of evidence but also dependent pieces of evidence This new approach turns out to be consistent with traditional probability theory It is more powerful than Dempster s combination rule at combining dependent evidence