When defects interact and the results of those interactions cannot be predicted with simulations, each possible defect combination must be included in the knowledge base. This results in an explosion of possible alternatives, greatly increased knowledge acquisition effort, slower processing, and increased maintenance effort. Other currently successful approaches to diagnosing multiple interacting defects include those using complete simulation models and statistical approaches. Complete simulation models are not available or cannot feasibly be constructed for many diagnostic problems. Statistical approaches depend on the availability of large numbers of cases to generate the statistics, and often do not produce an explanation for proposed diagnoses other than the statistics.
Many users describe statistics alone as unsatisfactory for aiding with important decisions.
IEEE Intelligent Systems, Vol. A Threaded Bibliography and Brief Commentary, Journal of the American Medical Informatics Association, Vol. The probabilistic Model and Inference Algorithms. Methods of Information in Medicine, Vol. Johnson, P. E., Moen, J. B., and Thompson, W. B., Garden Path Errors in Diagnostic Reasoning , in Expert System Applications, eds.