This introduction to the design of expert systems is written in an easy-to-read style and offers practical examples for each new topic presented. Emphasis is less on the intracacies of programming language, more on explanation. Defines what expert systems are, and discusses knowledge representation and inference. Chapters also cover logic, two-valued inference, inexact and semi-exact reasoning, advanced tools and topics, and draw on studies of human cognition to motivate technical definitions. Each chapter has an introduction and a summary, and provides suggestions for further reading. Contains student projects.