The Role of Tuning Uncertain Inference Systems

Heckerman (1], for example, shows that the equations that define MYCIN's certainty factors can be translated into probabilistic terms. Other studies, however, have attempted to use the answers provided by probability theory as a norm against which the accuracy of heuristic formalisms can be measured [2,3,4]. These studies differed somewhat in implementation, but each began with example inference networks. Next, new values were assigned to the evidence nodes, as though additional information were being supplied by a user. Finally, conclusion node values were calculated which reflected the new information, according to the heuristic formalisms under consideration and also according to a probablistic method which provided the minimum *This research was conducted under the McDonnell Douglas Independent Research and Development program.