Intentions and Information in Discourse

This paper is about the flow of inference between communicative intentions, discourse structure and the domain during discourse processing. We augment a theory of discourse interpretation with a theory of distinct mental attitudes and reasoning about them, in order to provide an account of how the attitudes interact with reasoning about discourse structure

A Cognitive Model for Conversation

International audienceThis paper describes a symbolic model of rational action and decision making to support analysing dialogue. The model approximates principles of behaviour from game theory, and its proof theory makes Gricean principles of cooperativity derivable when the agents’ preferences align

Knowledge, Causality and Temporal Representation

In this paper, a formal semantic framework is developed in order to account for the temporal semantics of text. The theory is able to represent and reason about both semantic issues, which are independent of world knowledge (wk), and pragmatic issues, which are not, within a single logical framework. The theory will allow a text's semantic entailments to differ from its pragmatic ones, even though they are all derived within the same logic. I demonstrate that this feature of the theory gives rise to solutions to several puzzles concerning the temporal structure of text. 1 The Problem The purpose of this paper is to provide a formal account of the temporal semantics of text. The chief goal is to explain when a text is temporally coherent: it should not mislead the reader as to the order of the events reported. If John hits Max, causing Max to turn round (to face John), then text (1) reflects this while (2) distorts it: (1) John hit Max. Max turned round. (2) Max turned roun..

Understanding Focus: Pitch, Placement and Coherence

This paper presents a novel account of focal stress and pitch contour in English dialogue. We argue that one should analyse and treat focus and pitch contour jointly, since (i) some pragmatic interpretations vary with contour (e.g., whether an utterance accepts or rejects; or whether it implicates a positive or negative answer); and (ii) there are utterances with identical prosodic focus that in the same context are infelicitous with one contour, but felicitous with another. We offer an account of two distinct pitch contours that predicts the correct felicity judgements and implicatures, outclassing other models in empirical coverage or formality. Prosodic focus triggers a presupposition, where what is presupposed and how the presupposition is resolved depends on prosodic contour. If resolving the presupposition entails the proffered content, then the proffered content is uninteresting and hence the utterance is in-felicitous. Otherwise, resolving the presupposition may lead to an implicature. We regiment this account in SDRT

A comparison of parsing technologies for the biomedical domain

This paper reports on a number of experiments which are designed to investigate the extent to which current nlp resources are able to syntactically and semantically analyse biomedical text. We address two tasks: parsing a real corpus with a hand-built widecoverage grammar, producing both syntactic analyses and logical forms; and automatically computing the interpretation of compound nouns where the head is a nominalisation (e.g., hospital arrival means an arrival at hospital, while patient arrival means an arrival of a patient). For the former task we demonstrate that exible and yet constrained `preprocessing ' techniques are crucial to success: these enable us to use part-of-speech tags to overcome inadequate lexical coverage, and to `package up' complex technical expressions prior to parsing so that they are blocked from creating misleading amounts of syntactic complexity. We argue that the xml-processing paradigm is ideally suited for automatically preparing the corpus for parsing. For the latter task, we compute interpretations of the compounds by exploiting surface cues and meaning paraphrases, which in turn are extracted from the parsed corpus. This provides an empirical setting in which we can compare the utility of a comparatively deep parser vs. a shallow one, exploring the trade-o between resolving attachment ambiguities on the one hand and generating errors in the parses on the other. We demonstrate that a model of the meaning of compound nominalisations is achievable with the aid of current broad-coverage parsers

Multimodal Grammar Implementation

This paper reports on an implementation of a multimodal grammar of speech and co-speech gesture within the LKB/PET grammar engineering environment. The implementation extends the English Resource Grammar (ERG, Flickinger (2000)) with HPSG types and rules that capture the form of the linguistic signal, the form of the gestural signal and their relative timing to constrain the meaning of the multimodal action. The grammar yields a single parse tree that integrates the spoken and gestural modality thereby drawing on standard semantic composition techniques to derive the multimodal meaning representation. Using the current machinery, the main challenge for the grammar engineer is the nonlinear input: the modalities can overlap temporally. We capture this by identical speech and gesture token edges. Further, the semantic contribution of gestures is encoded by lexical rules transforming a speech phrase into a multimodal entity of conjoined spoken and gestural semantics.

Discourse relations and defeasible knowledge

This paper presents a formal account of the temporal interpretation of text. The distinct nat- ural interpretations of texts with similar syntax are explained in terms of defeasible rules charac- tcrising causal laws and Gricean-style pragmatic maxims. Intuitively compelling patterns of defea. sible entaJlment that are supported by the logic in which the theory is expressed are shown to underly temporal interpretation

A semantics and pragmatics for the pluperfect

We offer a semantics and pragmatics of the pluperfect in narrative discourse. We examine in a formal model of implicature, how the reader's knowledge about the discourse, Gricean-maxims and causation contribute to the meaning of the pluperfect. By placin