Artificial Intelligence (AI) has always been computer science's 'department of clever tricks'. It is concerned with leading-edge problems which are hard for computers even if - like speech and vision - they are easy for people. This book is a practical, do-it-yourself introduction and guide for the personal computer user and student of AI who wants to learn and profit from AI techniques. All the programs are in BBC BASIC. *The Authors* Richard Forsyth was a Senior Lecturer in Computing at the Polytechnic of North London until 1984. He now runs his own business, Warm Boot Limited, which specialises in machine-intelligence applications. His recent books include The BBC BASIC Idea and Expert Systems: Principles and Case Studies, both published by Chapman and Hall. Chris Naylor is currently a full time author, researcher and freelance journalist. His recent books include Build Your Own Expert System and Programs That Write Programs: Choosing and using program generators. He is also a regular contributor on artificial intelligence and allied topics to a wide range of publications, including Practical Computing and The Times. Also available in an Applesoft BASIC version.