An AI system that mimics the decision-making ability and judgment of a human expert primarily based on symbolic, logic-based approaches to AI. These rules-based systems were popularized in the late 1980s but proved to be overly complex and brittle and declined in popularity. Expert systems consist of a knowledge base that stores learned information, a rules base that identifies how different paths can result in results, and an inference engine that generates results using information from the knowledge base and rules base based on the input data. Expert systems also often include explanation facilities so you can see how input data results in outputs based on the knowledge base and rules.
