Jonathan Slocum

Machine translation systems

This collection brings together reports on six of the major machine translation projects in Europe, North America and Japan. The book provides a state-of-the-art and future prospects for machine translation and concludes with a machine(-aided) translation bibliography.

A Practical Comparison of Parsing Strategies

INTRODUCTION Although the l i terature dealing with formal and natural languages abounds with theoretical arguments of worstcase performance by various parsing strategies [e.g. , Grif f i ths & Petrick, 1965; Aho & Ullman, 1972; Graham, Harrison & Ruzzo, Ig80], there is l i t t l e discussion of comparative performance based on actual practice in understanding natural language. Yet important practical considerations do arise when writ ing programs to understand one aspect or another of natural language utterances. Where, for example, a theorist wi l l characterize a parsing strategy according to i ts space and/or time requirements in attempting to analyze the worst possible input acc3rding to ~n arbi t rary grammar s t r i c t l y l imited in expressive power, the researcher studying Natural Language Processing can be jus t i f ied in concerning himself more with issues of practical performance in parsing sentences encountered in language as humans Actually use i t using a grammar expressed in a form corve~ie: to the human l inguist who is writ ing i t . Moreover, ~ r y occasional poor performance may be quite acceptabl:, part icular ly i f real-time considerations are not invo~ed, e.g., i f a human querant is not waiting for the answer to his question), provided the overall average performance is superior. One example of such a situation is o f f l ine Machine Translation.

Machine Translation: its History, Current Status, and Future Prospects

Elements of the history, state of the art, and probable future of Machine Translation (MT) are discussed. The treatment is largely tutorial, based on the assumption that this audience is, for the most part, ignorant of matters pertaining to translation in general, and MT in particular. The paper covers some of the major MT R&D groups, the general techniques they employ(ed), and the roles they play(ed) in the development of the field. The conclusions concern the seeming permanence of the translation problem, and potential re-integration of MT with mainstream Computational Linguistics.

Machine translation: An American perspective

Translation of human languages was one of the first applications considered for digital computers. Indeed, the idea of mechanizing translation predated the invention of such machines, but it was only after World War II, when digital computers became generally available, that Machine Translation (MT) was taken up seriously [4]. This paper explores the field or MT from the viewpoint of an American researcher/developer, and is intended for nonspecialists. We will not dwell on historical details; see [4] for an introduction. Nor will we present a comprehensive survey of MT systems, nor a long bibliography, since [10], [11] provide these. Instead, we will concentrate on aspects of R & D that, in the authors opinion, are of critical importance in developing any large-scale Natural Language Processing (NLP) application, which MT exemplifies. Case studies will be drawn from our experience in developing an MT system that is now being marketed. For context, surrounding sections of this paper will sketch the history of MT, then outline the nature of the translation problem, present various methodological approaches to solving the problem, and, following the discussion of R & D issues, consider future directions for MT research.

A STATUS REPORT ON THE LRC MACHINE

This paper discusses the linguistic and computational techniques employed in the current version of machine Translation system being developed at the Linguistics Research Center of the University of Texas, under contract to Siemens AG in Munich, West Germany. We pay particular attention to the reasons for our choice of certain techniques over other candidates, based on both objective and subjective criteria. We then report the systems status vis-a-vis its readiness for application in a production environment, as a means of justifying our claims regarding the practical utility of the methods we espouse.

MORPHOLOGICAL PROCESSING IN THE NABU SYSTEM

The Nabu morphological processor is designed to perform a number of different functions, of which five have so far been identified: analysis, guessing (about unknown words), synthesis, defaulting (proposing the most likely inflectional paradigm for a new base form), and coding (producing all possible inflectional paradigm variants for a new base form). Complete or very substantial analyzers have been produced for a number of diverse languages; other functions have been implemented as well. This paper discusses our design philosophy, as well as our technique and its implementation.

Concept-lexeme-syntax triangles: a gateway to interlingual translation

NABU is a large, multilingual Natural Language Processing (NLP) system being developed at MCC for Human Interface applications. Although the NABU project is not considering Machine Translation (MT) as an implementation domain, it is not unreasonable to suppose that, given our multilingual orientation, some MT problems could be ameliorated if not solved by our theoretical approach. This paper addresses the problem of MT via thecognitive interlingua method, focusing on the representation of the lexicon in such a system, and its accommodation of various sources of knowledge for use by both man and machine: notably, in the latter case, morphology, syntax, and semantics. We propose a new theoretical framework — the NABU Word Lattice — as a means of integrating multiple sources of knowledge in a parsimonious fashion conducive to formal interpretation within, and the construction of, an MT system.