Knowledge and expertise in expert systems

An important trend in current artificial intelligence (A.I.) research concerns expert systems. Expert systems are computer programs that are able to solve complex problems at a high level of expertise (Buchanan & Shortliffe, 1984). Most are also capable of explaining why and how they came to a particular solution. They derive their capabilities from a body of knowledge about a particular domain. This knowledge comprises both declarative (factual) knowledge and procedural knowledge, i.e., knowledge describing how to solve particular problems.