Expert systems, also called "rule-based systems," are computer programs or sets of programs that use knowledge of a domain (a specific field or discipline) to act as an expert in that domain. Expert systems have been built for dozens of sub-fields in medicine, business, and science, making this one of the most successfully commercialized branches of artificial intelligence (AI).

History

During the early years of artificial intelligence, computer scientists primarily developed programs that solved well-defined, self-explanatory problems (e.g., game playing, machine translation, or symbolic integrations). These programs required clever reasoning techniques to manipulate the logical and mathematical problems they were presented, but they did not require much knowledge beyond those techniques.

In the 1960s researchers began to realize that to solve many interesting problems, the programs would not only need to be able to interpret the problems, but they would need background knowledge to understand...