This book collects a group of experiments directed toward making intelligent machines. Each of the programs described here demonstrates some aspect of behavior that anyone would agree require some intelligence, and each program solves its own kinds of problems. These include resolving ambiguities in word meanings, finding analogies between things, making logical and nonlogical inferences, resolving inconsistencies in information, engaging in coherent discourse with a person, and building internal models for representation of newly acquired information. Each of the programs has serious limitations, but the chapter authors provide clear perspectives for viewing both the achievements and limitations of their programs. But what is much more important than what these particular programs achieve are the methods they use to achieve what they do.