An Incremental Model of Anaphora and Reference Resolution Based on Resource Situations

Notwithstanding conclusive psychological and corpus evidence that at least some aspects of anaphoric and referential interpretation take place incrementally, and the existence of some computational models of incremental reference resolution, many aspects of the linguistics of incremental reference interpretation still have to be better understood. We propose a model of incremental reference interpretation based on Loebner’s theory of definiteness and on the theory of anaphoric accessibility via resource situations developed in Situation Semantics, and show how this model can account for a variety of psychological results about incremental reference interpretation

Deixis, binding and presupposition

Dynamic semantic accounts of presupposition have proven to quite successful improvements over earlier theories. One great advance has been to link presupposition and anaphora together (van der Sandt 92, Geurts 95), an approach that extends to integrate bridging and other discourse phenomena (Asher and Lascarides 1998a,b). In this extended anaphoric account, presuppositions attach, like assertions, to the discourse context via certain rhetorical relations. These discourse attachments constrain accommodation and help avoid some infelicitous predictions of standard accounts of presupposition. Further, they have interesting and complex interactions with underspecified conditions that are an important feature of the contributions of most presupposition triggers. Deictic uses of definites, on the other hand, seem at first glance to fall outside the purview of an anaphoric theory of presupposition. There seems to be little that a discourse based theory would have to say. I will argue, however, that a discourse based account can capture how these definites function in conversation. In particular such accounts can clarify the interaction between the uses of such deictic definites and various conversational moves. At least some deictic uses of definites generate presuppositions that are bound to the context via a rhetorical function that I'll call unchoring, which if successful entails a type of knowing how. If this anchoring function is accepted, then the acceptors know how to locate the referent of the definite in the present context. I'll concentrate here just on definites that refer to spatial locations, where the intuitions about anchoring are quite clear. But I think that this view extends to other deictic uses of definites and has ramifications for an analysis of de re attitudes as well

Semantic Ambiguity and Perceived Ambiguity

I explore some of the issues that arise when trying to establish a connection between the underspecification hypothesis pursued in the NLP literature and work on ambiguity in semantics and in the psychological literature. A theory of underspecification is developed `from the first principles', i.e., starting from a definition of what it means for a sentence to be semantically ambiguous and from what we know about the way humans deal with ambiguity. An underspecified language is specified as the translation language of a grammar covering sentences that display three classes of semantic ambiguity: lexical ambiguity, scopal ambiguity, and referential ambiguity. The expressions of this language denote sets of senses. A formalization of defeasible reasoning with underspecified representations is presented, based on Default Logic. Some issues to be confronted by such a formalization are discussed.Comment: Latex, 47 pages. Uses tree-dvips.sty, lingmacros.sty, fullname.st

The role of semantics in spoken dialogue translation systems

In this paper, we consider the role of semantics in the spoken dialogue translation systems. We begin by looking at some of the key properties of an existing spoken dialogue system, namely the sundial system which provides flight and train information over the telephone, and how these properties affect the design methodology and functionality of spoken translation systems. These properties include the effects of speech processing, designing the system to meet the needs of users, and an analysis model which clearly separates the linguistic, conceptual, pragmatic and task levels. In this model many task functionalities are dependent upon, and sometimes realizable by, the semantic and pragmatic analysis components. Central to this approach, is the use of underspecified semantic representations which are further specified as and when required by domain and/or task analysis. This model can be applied in the development of spoken translation systems with two important effects: monolingual semantic and pragmatic analysis can be carried out by processes independent of, but correlated with, the (translation) function of the system; and the main functions of the transfer processes is to further specifying the representations for the target language and to deal with mismatches between source and target language representations. We illustrate this approach with semantic analyses of German utterances required for translation in the verbmobil spoken dialogue translation system