EVIDENTIAL REASONING Will-l TEMPORAL ASPECTS

In the real world, one usually cannot gather enough evidence to completely determine the activity of a system. Typically, different pieces of evidence tell you about different aspects of the system with different certainties. Correlating these at a given point of time is a much studied problem. The problem becomes even less tractable when the evidence is acquired at different points in time. The system described in this paper uses frame-like objects called “models” that propagate the effects of a piece of evidence through time and uses Gordon and Shortliffe’s theory to combine the effects of the active models. These models do not require either a great deal of storage or that the evidence be processed in temporal order. Further, they seem to be a construct that the experts in our problems easily relate to. Results with test problems are consistent with the estimates of experts and run in not unreasonable time. problem that will show the kinds of issues the processing part of the system addresses but avoids the real life knowledge content.