expert system
computer program providing expert knowledge and procedures a computer program that emulates the reasoning and decision making of a human expert in a particular field. The main components of an expert system are the knowledge base, which consists of facts and rules about appropriate courses of action based on the knowledge and experience of human experts; the inference engine, which simulates the inductive reasoning of a human expert; and the user interface, which enables users to interact with the system. Expert systems may be used by nonexperts to solve well-defined problems when human expertise is unavailable or expensive, or by experts seeking to find solutions to complex questions. They are used for a wide variety of tasks, including medical diagnostics and financial decision making, and are an application of artificial intelligence.

