Telling Aardvarks from Zebras with an Expert System Written in SAS®

Expert systems are a branch of artificial intelligence that encapsulate the knowledge and behaviors of a subject matter expert in their domain of expertise. The expert’s automated services then become available throughout the enterprise. Classification and diagnosis represent an important class of problems that have traditionally been a major objective of expert systems. An object-oriented expert system is now available that will allow a user to create knowledge bases written in Base SAS or a combination of Base SAS and SAS Component Language (SCL). Implementation of a knowledge base to classify mammals is described here as an example of the expert system used for this general class of knowledge bases. The discussion includes: identifying objects and placing them in a search tree, object design, method design, method inheritance, blackboard databases, and search engine control. Mammals are chosen as a subject because their classification is not an overly complex design, and because everyone is to some degree a subject matter expert.