As the contributions to this book make clear, a fundamental change is taking place inthe study of computational linguistics analogous to that which has taken place in the study ofcomputer vision over the past few years and indicative of trends that are likely to affect futurework in artificial intelligence generally.The first wave of efforts on machine translation and theformal mathematical study of parsing yielded little real insight into how natural language could beunderstood by computers or how computers could lead to an understanding of natural language. Thecurrent wave of research seeks both to include a wider and more realistic range of features found inhuman languages and to limit the dimensions of program goals. Some of the new programs embody forthe first time constraints on human parsing which Chomsky has uncovered, for example. The isolationof constraints and the representations for their expression, rather than the design of mechanismsand ideas about process organization, is central to the work reported in this volume. And if presentgoals are somewhat less ambitious, they are also more realistic and more realizable. Contents:Computational Aspects of Discourse, Robert Berwick; Recognizing Intentions from Natural LanguageUtterances, James Allen; Cooperative Responses from a Portable Natural Language Data Base QuerySystem, Jerrold Kaplan; Natural Language Generation as a Computational Problem: An Introduction,David McDonald; Focusing in the Comprehension of Definite Anaphor, Candace Sidner; So What Can WeTalk About Now? Bonnie Webber. A Preface by David Israel relates these chapters to the generalconsiderations of philosophers and psycholinguists.Michael Brady is Senior Research Scientist at theMIT Artificial Intelligence Laboratory. The book is included in the MIT Press ArtificialIntelligence Series.