Interpreting Singular Definite Descriptions in Database Queries

INTERPRETING SINGULAR DEFINITE DESCRIPTIONS IN DATABASE QUERIES Genevieve Berry-Rogghe Department of Computer and Information Science Temple University Philadelphia, PA 19122 USA ABSTRACT The paper examines some of the cha- racteristic features of natural langua- ge interaction with a database system and its implications for the processing of singular definite descriptions. Some proposals are made for assessing the uniqueness claim of the singular defini- te article in the context of retrieval from a relational database. Other stan- dard assumptions such as the extensio- nal evaluation and referent evaluation exclusively in the database - rather than within the discourse model - are critically examined. INTRODUCTION A comprehensive treatment of the phe- nomenon of singular definite description in natural language processing constitu- tes a research program par excellence in the field of cognitive science. Not only does it involve the various cognitive disciplines but also the integration of the traditional levels of analysis, na- mely the syntactic, semantic and pragma- tic levels as well as including a "per- formance" or processing level dealing with mechanisms for memory managment of referring expressions. Linguistic theo- ries initially attempted to account for the syntactic conditions of well-formed- ness governing the introduction of sin- ~ular definite nounphrases in sentences by postulating co-referentiality with a previously occurring indefinite noun- phrase having the same referential in- dex. But it became clear that the postu- lated requirements of co-referentiality could only be adequately stated by means of an extended notion of "discourse re- ferent" (see Karttunen 1968 b). Logicians and philosophers of language since Russell have studied problems of reference and of the logical form of re- ferring expressions occurring in various contexts (for a selection, see Linsky 1971). But it was pointed out in Donnel- lan 1966 that a strictly truthfunctional analysis of singular definite expres- sions may in certain situations evaluate to a referent which was not intended by the speaker. Accounting for the inten- tions of the speaker introduces the prag- matic point of view of referring as a speech act (see Searle 1966). How the speaker proceeds in describing an object s/he has in mind so that it may be cor- rectly identified by the hearer and how the hearer perceives the intentions of the speaker to accordingly process des- criptions has been the object of psycho- logically oriented research in the area of definite reference (e.g. Clark/Mar- shall 1981 and Ortony-Anderson 1977). In Artificial Intelligence, research on de- finite descriptions has mainly proposed computational models to resolve anapho- ric reference by postu21ating certain in- ference mechanisms (e.g. Charnlak 1972 and Rieger 1974) or mechanisms for detec- ting and managing dialogue focus (e.g. Grosz 1981 and Sidner 1979). Considering practical applications in the computer processing of natural lan- guage it may be said that next to none of this large body of research has been incorporated. Most natural language front-ends to a standard database system support none or very primitive reference resolution and treat the singular defini- te article as an existential quantifier. This state of …

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