Lauri Carlson

Focus and Dialogue Games

The present paper, long as it is, is an excerpt of a monograph manuscript entitled Dialogue Games — A Game-Theoretical Approach to Text Linguistics. As the name indicates, the more comprehensive work develops the intonational ideas presented here in the wider perspective of a game-theoretical theory of textual concepts (such as theme, rheme, topic, old vs. new information, textual connectedness)*.

PRONOUNS OF LAZINESS IN GAME-THEORETICAL SEMANTICS

In this paper, the behavior of so-called pronouns of laziness is studied in terms of Hintikkas game-theoretical semantics. It is seen that pronouns of laziness result from a violation of a prima facie restriction on the use of game rules in the presence of pronominal ties in the input sentence. The disposition to such violations is conditioned among other factors by the principles governing the order of application of different game rules. Additional factors contributing to the availability of pronouns of laziness are discussed, as well as the relation of this phenomenon to certain other important semantical distinctions.

Quantified Hintikka-style epistemic logic

This paper contains a formal treatment of the system of quantified epistemic logic sketched in Appendix II of Carlson (1983). Section 1 defines the syntax and recapitulates the model set rules and principles of the Appendix system. Section 2 defines a possible worlds semantics for this system, and shows that the Appendix system is complete with respect to this semantics. Section 3 extends the system by an explicit truth operatorT “it is true that” and considers quantification over nonexistent individuals. Section 4 formalizes the idea of variable identity criteria typical of Hintikkian epistemic logic.

Unification as a Grammatical Tool

The present paper is an introduction to unification as a formalism for writing grammars for natural languages. The paper is structured as follows. Section 1 briefly describes the history and the current scene of unification based grammar formalisms. Sections 2–3 describe the basic design of current formalisms. Section 4 constitutes a tutorial introduction to a representative unification based grammar formalism, the D–PATR system of Karttunen (1986). Sections 5—6 consider extensions of the unification formalism and its limitations. Section 7 examines implementation questions and addresses the question of the computational complexity of unification. — Some notes on terminology.

Utility Evaluation of Tools for Collaborative Development and Maintenance of Ontologies

Ontologies lend themselves for resolving ambiguities in a wide range of applications, including mashups from diverse third-party information sources, and human-and machine-readable specifications of electronic business services (eBS). While tool support exists for the development and maintenance of ontologies, the question remains unanswered what is the degree of utility of these tools in the context of ambiguity resolution, e.g., while discovering eBS. In this paper, we fill the gap by performing an ontology-tool evaluation that allows a comparison of their utility. Based on a carefully selected set of requirements and criteria, we conduct a survey involving leading ontology-tool providers. One of the principal requirements is the collaborative ontology development and maintenance. The paper provides a detailed analysis of survey results.

Modelling the Semantics of Calendar Expressions as Extended Regular Expressions

This paper proposes modelling the semantics of natural-language calendar expressions as extended regular expressions (XREs). The approach covers expressions ranging from plain dates and times of the day to more complex ones, such as thesecond Tuesdayfollowing Easter. Expressions denoting disconnected periods of time are also covered. The paper presents an underlying string-based temporal model, sample calendar expressions with their XRE representations, and possible applications in temporal reasoning and natural-language generation.

Ontology-based Knowledge in Interactive Maintenance Guide

This paper describes 4M, a language technology research project where a dialogue system is applied on a mobile platform in a maintenance job scenario. The human-machine interface uses speech synthesis and recognition, assisted with a hypertext display. We describe a modular agent architecture, composed of independent program components which are implemented by or communicate using ontology programming techniques. Domain content and lingware are developed and shared using standard Web ontology formats and ontology-aware offline tools. A contribution of the project is the attention paid to standardization to help provide the system with new content and to migrate it to new domains, languages and purposes

Logic for dialogue games

The purpose of this paper is to work toward an explicit logic and semantics for a game theoretically inspired theory of action. The purpose of the logic is to explicate the conceptual machinery implicit in the dialogue-game model of rational discourse developed in Carlson (1983).A variety of ideas and techniques of modal and philosophical logic are used to define a model structure that generalizes the game theoretical notion of a game in extensive form (von Neumann and Morgenstern, 1944). Relative to this model structure, semantic characterizations are given to the action-theoretic notions oftime, possibility, belief, preference, ability, intention, action, andrationality. The unification of these characterizations under the game-theoretical paradigm leads to insights about the logical interdependences between these concepts.The resulting theory of rational interaction is applied to the explication of rational dialogue. The main benefit of the enterprise for a theory of rational dialogue is that concepts and results of game theory become accessible to the explication of dialogue. In particular, the task of proving the logical coherence of a discourse is reduced to the task of showing the rationality of strategy choices made in an associated dialogue game.

Independent transfer using graph unification

We present a MT system that applies graph unification in transfer from English to Finnish. The work described below is an outgrowth of a multilingual MT project initiated by the IBM in 1987 with the aim of studying multilingual translation using a common English language parser.The transfer system presented here is independent of the parsing and generation modules. Any source language parser can be used whose output can be expressed in a directed graph form. The transfer system is responsible for generating target language phrase structure. Target language word order and morphology are left to the generation modules.The transfer system is lexically based. Transfer rules, presented in the form of bilingual graphs, are declarative statements of symmetric transfer relationships between words, phrases or constructions in the two intertranslatable languages.Transfer is structure driven in that the transfer algorithm traverses the source language graph, nondeterministically trying to apply the relevant transfer rules in the lexicon. Each successful transfer yields a bilingual graph, whose target language half is extracted and subjected to linearization and morphological generation.The main focus of attention in our project is the development of the lexicon subsystem. The lexicon system consists of separate transfer and monolingual lexicons and a common lexicon of language independent definitions.

Two string-based finite-state models of the semantics of calendar expressions

This paper presents two string-based finite-state approaches to modelling the semantics of natural-language calendar expressions: extended regular expressions (XREs) over a timeline string of unique symbols, and a string of hierarchical periods of time constructed by finite-state transducers (FSTs). The approaches cover expressions ranging from plain dates and times of the day to more complex ones, such as the second Tuesday following Easter. The paper outlines the representations of sample calendar expressions in the two models, presents a possible application in temporal reasoning, and informally compares the models.