1. Knowledge

1.1 General

The design of knowledge-based systems, and in particular expert systems, is a major field in artificial intelligence (AI). Such systems are designed to approximate the performance of human experts in limited domains, by exploiting a body of knowledge acquired mainly from these experts. Most often, they are decision-support aids. First appearing around 1975, they have had a definite impact on AI, as well as a sometimes exaggerated media impact. The term expert system has been replaced by the more general concept of knowledge-based system (KBS), which can be found in a variety of fields.