Artificial intelligence (AI) is the field of scientific inquiry concerned with designing machine systems that can simulate human mental processes. The field draws upon theoretical constructs from a wide variety of disciplines, including mathematics, psychology, linguistics, neurophysiology, computer science, and electronic engineering. Some of the most promising developments to come out of recent AI research are "expert" systems or computer programs that simulate the problem-solving techniques of human experts in a particular domain. This paper reviews contemporary work in expert systems. It includes: (1) a brief history of AI research; (2) an overview of major lines of inquiry in the field, considering pattern recognition, robotics, and problem-solving; (3) a detailed discussion of the structure, design, and limitations of expert systems; and (4) a discussion of the role that expert systems might play in education. Two appendices are included. The first presents an example of interaction with an expert system; the second lists major systems that are currently in use or under development in the categories of bioengineering, chemistry, computer hardware, computer software, education, engineering, general purpose systems and artificial intelligence utilities, law, manufacturing and industry, mathematics, medicine, the military, and resource exploration. (JN)