Grishman R. Computational Linguistics. An Introduction

Cambridge University Press, 1989. — 203 p.Natural language is an integral part of our lives. Language serves as the primary vehicle by which people communicate and record information. It has the potential for expressing an enormous range of ideas, and for conveying complex thoughts succinctly. Because it is so integral to our lives, however, we usually take its powers and influence for granted.
The aim of computational linguistics is, in a sense, to capture this power. By understanding language processes in procedural terms, we can give computer systems the ability to generate and interpret natural language. This would make it possible for computers to perform linguistic tasks (such as translation), process textual data (books, journals, newspapers), and make it much easier for people to access computer-stored data. A well-developed ability to handle language would have a profound impact on how computers are used.
The potential for natural language processing was recognized quite early in the development of computers, and work in computational linguistics - primarily for machine translation - began in the 1950s at a number of research centers. The rapid growth in the field, however, has taken place mostly since the late 1970s. A 1983 survey by the Association for Computational Linguistics (Evens and Karttunen 1983) listed 85 universities granting degrees in computational linguistics. A 1982 survey by the ACM (Association for Computing Machinery) Special Interest Group on Artificial Intelligence (Kaplan 1982) listed 59 university and research centers with projects in computational linguistics, and the number continues to grow. This growth has spawned a large literature, in journals, conference proceedings, and anthologies. There have, however, been few books which try to survey this field in a unified fashion. The volume before you is an attempt to fill this gap. It was initially prepared as lecture notes for a course entitled Advanced Topics in Artificial Intelligence which I taught at New York University in the Spring of 1980, and was subsequently revised for courses in 1982 and 1984.
To attempt a unified survey of a field where there is sharp disagreement even about basic approaches may seem foolhardy. I freely admit that some points of view have received short shrift, and that the organization reflects the biases of my own research efforts. I hope that, despite these inadequacies, this survey will be helpful to some of those starting off in computational linguistics.
People come to computational linguistics with a wide range of backgrounds and interests; I have tried to organize this survey to accommodate this variety. I assume that readers have some background in computer science, so that they can grasp the descriptions of algorithms and visualize how they might be implemented. At the least, readers should have a knowledge of programming and data structures - how lists and trees are represented. More advanced material, in programming languages, compilers, or the basics of artificial intelligence, is not essential but will aid in appreciating some of the material. In addition, readers should have some familiarity with finite mathematics - trees, sets, formal languages, and formal logic. For those with only a passing acquaintance with formal languages and logic, I have provided brief background sections on these topics, along with references for further study. I have also included some historical (or pseudo-historical) material in the narrative. I felt that some idea of how computational linguistics has developed would be worthwhile to the novice researcher. Also, in view of the many different approaches which are still being considered, I thought that a presentation of approaches which were tried and found wanting in the past would be useful. More than once, I have heard at conference 'novel' approaches which, in different guise, had been considered and rejected a decade ago. A review of past efforts will allow readers to direct their energies toward genuinely novel investigations.What is computational linguistics?
Syntax analysis
Semantic analysis
Discourse analysis and information structuring
Language generation