The Formation of Composite Hypotheses in Diagnostic Problem Solving: An Exercise in Synthetic Reasoning

Abstract

The INTERNIST system, which is a computerbased diagnostic problem solver having Internal Medicine as its domain of discourse, employs a novel attention focusing heuristic in order to deal sequentially with the component parts of a complex clinical problem. The strategy of sequential problem formation and solution has proved to be effective in sorting out the complexities and rendering a correct diagnosis in the great majority of clinical cases tested. Experience with the system suggests, however, that many aspects of the search process could be significantly enhanced if it were possible to attend to the various component problems and their interrelationships simultaneously. Recent work on a successor system has been directed towards the development of strategies for the synthesis and analysis of composite hypotheses, which may be expected to yield more rapid convergence to the correct conclusion in many cases, and in at least some cases to prevent missed diagnoses.