ABSTRACT
In this chapter the author explains the increasingly important matter of Knowledge-based systems and Expert systems. Knowledge-based systems contain large amounts of varied knowledge which is brought to bear on a given task. The two kinds of knowledge needed by an expert are the facts of the subject and the heuristics of the subject. The two kinds of knowledge needed by an expert are the facts of the subject and the heuristics of the subject. The knowledge elicitation state of constructing an expert system is carried out by the knowledge engineers, who have, when the heuristic knowledge is made explicit, to formulate it appropriately for the computer. The knowledge-base of INTERNIST is of two basic types: diseases and manifestations in the form of case histories, symptoms, physical signs and laboratory findings. The knowledge-base has been structured so that abnormal findings are used to abduce disease hypotheses directly.
