Articles

A novel formalism is presented for Earley-like parsers. It accommodates the simulation of non-deterministic pushdown automata. In particular, the theory is applied to non-deterministlc LRoparsers for RTN grammars. 1...

Near-term spoken language systems will likely be limited in their interactive capabilities. To design them, we shall need to model how the presence or absence of speaker interaction in- fluences spoken discourse patterns in different types of tasks. In this research, a comprehensive examination is provided of the discourse struc- …...

An effective procedure for automatically acquiring a new set of disambiguation rules for an existing deterministic parser on the basis of tagged text is presented. Performance of the automatically ac- quired rules is much better than the existing hand- written disambiguation rules. The success of the acquired rules depends on …...

NLP systems, in order to be robust, must handle novel and ill-formed input. One common type of error involves the use of non-standard prepositions to mark arguments. In this paper, we argue that such errors can be handled in a systematic fashion, and that a system designed to handle them …...

Conversationally relevant descriptions are definite descriptions that are not merely tools for the iden- tification of a referent, but are also crucial to the dis- course in other respects. I analyze the uses of such descriptions in assertions as conveying a particular ~ype of conversational implicatures. Such implics- tures can …...

This paper describes the referring expression generation mechanisms used in EPICURE, a com- puter program which produces natural language descriptions of cookery recipes. Major features of the system include: an underlying ontology which permits the representation of non-singular entities; a notion of diacriminatory power, to determine what properties should be …...

This paper presents a computational model of verb acquisition which uses what we will call the princi- ple of structured overeommitment to eliminate the need for negative evidence. The learner escapes from the need to be told that certain possibili- ties cannot occur (i.e., are "ungrammatical") by one simple expedient: …...

I.I Sketch of Proposal We propose a semantics for locative expressions such as near Jones or west of Denver, an impor- tant subsystem for NLP applications. Locative ex- pressions denote regions of space, and serve as argu- ments to predicates, locating objects and events spa- tially. Since simple locatives occupy …...

This paper describes a 'Logical Form' target language for representing the literal mean- ing of English sentences, and an interme- diate level of representation ('Quasi Logical Form') which engenders a natural separation between the compositional semantics and the processes of scoping and reference resolution. The approach has been implemented in …...

Unification-Based Semantic Interpretation Robert C. Moore Artificial Intelligence Center SRI International Menlo Park, CA 94025 We show how unification can be used to spec- ify the semantic interpretation of natural-language expressions, including problematical constructions involving long-distance dependencies. We also sketch a theoretical foundation for unification- based semantic interpretation, and compare …...

Feature structures are informational elements that have been used in several linguistic theories and in computa- tional systems for natural-language processing. A logi- caJ calculus has been developed and used as a description language for feature structures. In the present work, a framework in three-valued logic is suggested for defining …...

We propose a model for transfer in machine translation which uses a rewriting system for typed feature structures. The grammar definitions describe transfer relations which are applied on the input structure (a typed feaane structure) by the interpreter to produce all possible transfer pairs. The formalism is based on the …...

We present an algorithm for generating strings from logical form encodings that improves upon previous algorithms in that it places fewer restric- tions on the class of grammars to which it is ap- plicable. In particular, unlike an Earley deduction generator (Shieber, 1988), it allows use of seman- tically nonmonotonic …...

I examine how discourse anaphoric uses of the definite pronoun it contrast with similar uses of the demonstrative pronoun thai. Their distinct contexts of use are characterized in terms of two contextual features--perslstence of grammati- cal subject and persistence of gr,~mmatical form--which together demonstrate very clearly the interrelation among lexical …...

A grammatical description often applies to a linguistic object only when that object has certain features. Such conditional descriptions can be indirectly modeled in Kay's Functional Unification Grammar (FUG) using functional descriptions that are embedded within disjunctive alternatives. An ex- tension to FUG is proposed that allows for a direct …...

We have analyzed definitions from Webster's Seventh New Collegiate Dictionary using Sager's Linguistic String Parser and again using basic UNIX text processing utilities such as grep and awk. Tiffs paper evaluates both procedures, compares their results, and discusses possible future lines of research exploiting and combining their respective strengths....

We apply a complexity theoretic notion of feasible learnability called "polynomial learnabillty" to the eval- uation of grammatical formalisms for linguistic descrip- tion. We show that a novel, nontriviai constraint on the degree of ~locMity" of grammars allows not only con- text free languages but also a rich d~s of …...

Automatic book indexing systems are based on the generation of phrase struc- tures capable of reflecting text content. • Some approaches are given for the automatic construction of back-of-book indexes using a syntactic analysis of the available texts, followed by the identifica- tion of nominal constructions, the assign- ment of …...

Speakers convey much of the information hearers use to interpret discourse by varying prosodic features such as PHRASING, PITCH ACCENT placement, TUNE, and PITCH P.ANGE. The ability to emulate such variation is crucial to effective (synthetic) speech generation. While text-to- speech synthesis must rely primarily upon structural in- formation to …...

As our understanding of natural language gener- ation has increased, a number of tasks have been separated from realization and put together un- der the heading atext planning I. So far, however, no-one has enumerated the kinds of tasks a text planner should be able to do. This paper describes …...