An empirical comparison of three inference methods

In this paper, an empirical evaluation of three infer­ ence methods for uncertain reasoning is presented in the context of Pathfinder, a large expert system for the diagnosis of lymph node pathology. The inference procedures evaluated are (1) Bayes' theorem, a:ssum­ ing evidence is conditionally independent given each hypothesis, (2) odds-likelihood updating, assuming evidence is conditionally independent given each hy­ pothesis and given the negation of each hypothesis, and (3) a inference method related: to the Dempster­ Shafer theory of belief. A decision-theoretic approach is introduced for evaluating the performance of ex­ pert systems. This approach, when combined with . a more traditional expert-rating methcx\ for evalua­ tion, provides insights about various components of the inference process.