From devika@cs.cornell.edu Wed Nov 30 17:20:44 EST 1994 Article: 25620 of comp.ai Newsgroups: comp.ai,comp.ai.edu Path: cantaloupe.srv.cs.cmu.edu!das-news2.harvard.edu!news2.near.net!news.mathworks.com!news.kei.com!travelers.mail.cornell.edu!cornell!devika From: devika@cs.cornell.edu (Devika Subramanian) Subject: A review of Russell and Norvig's new AI text Message-ID: <1994Nov30.151429.14332@cs.cornell.edu> Organization: Cornell Univ. CS Dept, Ithaca NY 14853 Date: Wed, 30 Nov 1994 15:14:29 GMT Lines: 93 Xref: glinda.oz.cs.cmu.edu comp.ai:25620 comp.ai.edu:2134 A brief review of "Artificial Intelligence: A Modern Approach" Stuart Russell and Peter Norvig Prentice Hall, December 1994. ISBN 0-13-103805-2 by Devika Subramanian, Cornell University While the enterprise of artificial intelligence has often been defined around the dream of intelligent agents, Russell and Norvig's book is the first attempt to present the technical accomplishments of AI to a broad scientific audience in the context of embedded agents acting in real-world environments. The book is not merely an expositional triumph; Russell and Norvig achieve a unique synthesis of concepts and algorithms in AI that have evolved in very disparate sub-communities of the field. The book draws on ideas from logic, decision theory, control theory, Markov processes, economics, on-line algorithms, complexity theory, probability and statistics and information theory, to coherently present methods in AI in a jargon-free manner. This makes the book an ideal introduction to newcomers to AI from computer science as well as other branches of science and engineering. For seasoned practitioners, it offers a new, thought-provoking way to understand AI. The book is organized into eight sections. The first section begins with a brief history of AI and introduces the basic vocabulary for describing agents embedded in task environments. The last section (Section VIII) comprises a beautiful essay on the philosophical foundations of AI and an engaging commentary on the current state and future challenges facing AI. The sections in between constitute the technical meat of the book. Section II highlights general problem-solving methods for embedded agents and includes informed search methods that take resource constraints into account. The third section emphasizes the role of knowledge in decision-making and presents an array of methods for representing and reasoning with logical or categorical knowledge. Section IV presents planning as reasoning about action choice; contemporary planning and replanning methods are presented as specializations of the general methods of logical reasoning introduced in the third section. Section V introduces probability and decision theory as tools for agents acting under uncertainty. It explains how belief networks can be used to represent uncertain knowledge and describes decision-making methods based on them. The sixth section focuses on learning and adaptation in intelligent agents. It presents a unified model of learning, a brief introduction to computational learning theory, as well as specific techniques such as decision-tree learning, neural networks, and a new method for learning belief networks. It also includes a tutorial exposition of recent work in reinforcement learning, as well as the knowledge-based inductive logic programming method. Section VII focuses on interactions of the agent with the external world: natural language communication, perception and robotics. Russell and Norvig have recruited established experts (Jitendra Malik and John Canny) to cover the specialized topics of perception and robotics, ensuring a uniformly high quality to all of the technical material in the book. The book is hefty: over 900 pages in all. However, almost 200 pages are devoted to items sometimes missing from AI texts: a very thorough index, a truly massive bibliography, "Historical Notes" sections that are researched in depth and make fascinating reading, and a large collection of excellent exercises. This is perhaps not the place to go through all the book's chapters in detail, but some deserve special mention. The second chapter on agents is brilliant; it puts the entire history of work in AI in perspective and explains WHY people built the algorithms that were built. This is the first question that most first-timers to AI have, and this is answered up front. The chapters on reasoning about uncertainty are by far the best tutorial exposition of material on probability and belief networks: they make the original papers in the area much more accessible. Judged from all respects, this is a remarkably comprehensive and incisive treatment of the field. The book is well-written and well-organized and includes uniform and clear descriptions of all major AI algorithms. The authors have managed to describe key concepts with technical depth and rigour without falling prey to stodginess and Greek-symbolitis. AI is presented as a set of inter-related design principles, rather than a grab bag of tricks. The book brims with optimism and contagious excitement about the frontiers of AI. I recommend it without reservation to anyone interested in the computational study of intelligence, whether they be undergraduate or graduate students or senior scientists in the field. About the reviewer: Subramanian is an Assistant Professor at the Computer Science Department at Cornell University. Her interests are in AI, its theoretical foundations and practical applications in design, scheduling and molecular biology. She has been teaching AI at the undergraduate and graduate levels for about five years.