Sous-langage d'application et LTAG : le système EGAL

Colloque avec actes et comité de lecture.Nous présentons un système dédié à la conception et au test d'un sous-language d'application pour un système de Dialogue Homme-Machine. EGAL se base sur une grammaire LTAG générale de la langue qui est spécialisée à une application donnée à l'aide d'un corpus d'entraînement. Un double effort a porté premièrement sur la définition d'une méthodologie précise passant par une expérimentation de type Magicien d'Oz pour le recueil des corpus et des estimations de la représentativité du corpus de conception, et, deuxièmement, sur la spécification des composants du système en vue de mettre en oeuvre des outils convivaux, génériques et ouverts

Survey of the State of the Art in Natural Language Generation: Core tasks, applications and evaluation

This paper surveys the current state of the art in Natural Language Generation (NLG), defined as the task of generating text or speech from non-linguistic input. A survey of NLG is timely in view of the changes that the field has undergone over the past decade or so, especially in relation to new (usually data-driven) methods, as well as new applications of NLG technology. This survey therefore aims to (a) give an up-to-date synthesis of research on the core tasks in NLG and the architectures adopted in which such tasks are organised; (b) highlight a number of relatively recent research topics that have arisen partly as a result of growing synergies between NLG and other areas of artificial intelligence; (c) draw attention to the challenges in NLG evaluation, relating them to similar challenges faced in other areas of Natural Language Processing, with an emphasis on different evaluation methods and the relationships between them.Comment: Published in Journal of AI Research (JAIR), volume 61, pp 75-170. 118 pages, 8 figures, 1 tabl

Fusion de contraintes pour la synchronisation des modalités et pour la résolution des références dans un énoncé multimodal

Avant de résoudre les références aux objets et aux lieux d'un énoncé multimodal associant parole et geste de désignation, il est nécessaire de mettre en correspondance chaque geste avec le segment linguistique qui lui correspond. Pour cela, nous exprimons les contraintes syntaxiques, sémantiques et pragmatiques apportées par (a) les expressions référentielles et (b) les gestes, compte tenu de la disposition des objets et de leurs éventuels regroupements perceptifs. Une formalisation logique de ces contraintes et leur fusion permet d'aboutir à des hypothèses de correspondances puis à l'identification des référents. Nous exprimons alors la forme propositionnelle de l'énoncé permettant au système de retrouver les fonctions de l'application à exécuter. Malgré les nombreuses hypothèses faites sur chaque expression prise individuellement, nous montrons que le contenu propositionnel dans son ensemble est souvent le même. Cette méthode nous semble particulièrement prometteuse, tant parce qu'elle permet d'identifier les facteurs précis intervenant dans l'intégration de la langue et du geste, qu'en ce qu'elle permet d'envisager très facilement une implantation informatique

Designing Service-Oriented Chatbot Systems Using a Construction Grammar-Driven Natural Language Generation System

Service oriented chatbot systems are used to inform users in a conversational manner about a particular service or product on a website. Our research shows that current systems are time consuming to build and not very accurate or satisfying to users. We find that natural language understanding and natural language generation methods are central to creating an e�fficient and useful system. In this thesis we investigate current and past methods in this research area and place particular emphasis on Construction Grammar and its computational implementation. Our research shows that users have strong emotive reactions to how these systems behave, so we also investigate the human computer interaction component. We present three systems (KIA, John and KIA2), and carry out extensive user tests on all of them, as well as comparative tests. KIA is built using existing methods, John is built with the user in mind and KIA2 is built using the construction grammar method. We found that the construction grammar approach performs well in service oriented chatbots systems, and that users preferred it over other systems

Proceedings

Proceedings of the Ninth International Workshop on Treebanks and Linguistic Theories. Editors: Markus Dickinson, Kaili Müürisep and Marco Passarotti. NEALT Proceedings Series, Vol. 9 (2010), 268 pages. © 2010 The editors and contributors. Published by Northern European Association for Language Technology (NEALT) http://omilia.uio.no/nealt . Electronically published at Tartu University Library (Estonia) http://hdl.handle.net/10062/15891

Choice of syntactic structure during language production: The production of unbounded dependencies

During language production, conceptual messages are encoded into a target language and articulated. Existing models of language production assume several stages of processing including a conceptual level, a level where lexical selection and syntactic processing occurs and a level where morphological and phonological features are added ready for production (e.g. Levelt et al., 1999). Previous research has considered how lexical and syntactic information could be stored via lemma (Kempen & Huijbers, 1983), syntactic nodes (Levelt at el., 1999) and combinatorial nodes (Pickering & Braingan, 1998), but little is understood about how syntactic structures are selected. This thesis examines how constituent structures are selected by investigating choice of structure in unbounded dependencies such as Which jug with the red spots is the nun giving the monk? and how this is affected by factors such as verb-subcategorisation preferences and global sentence structure complexity. A series of language production experiments investigate how global structure complexity and verb-subcategoricatisaion preferences affect choice of syntactic structure at the clause level in unbounded dependencies. A picture description task reveals an unusual preference for the dispreferred passive voice structure as a result of global structural complexity. Sentence recall experiments demonstrate that both global structural complexity and verb-subcategorisation preferences can affect choice of structure and that competition between these factors decides the final structure. Finally, syntactic priming experiments show that processing mechanisms are shared between simple matrix clause structures and unbounded dependency clause structures, but that the influence of these shared mechanisms vary between the different structure types. This could be attributed to a modal of processing where choice of structure is decided by competition between structure representations which are influenced by different factors in different global syntactic conditions. The results suggest that choice of syntactic structure is decided through competition between possible structures. These possible structures may receive further activation or inhibition from other factors such as global structural complexity or verb-subcategorisation preferences and thematic fit. Global structural complexity may influence structure preferences through increased processing load or through attempts to integrate the clause structure with another global structure. Thematic role arguments may influence structure through a preference that syntactic roles fit with specified thematic roles. (e.g. experiencer as subject). This model assumes parallel processing of possible structures and individual structures within a complex larger structure. It also assumes an incremental model of processing which attempts to integrate structures as soon as possible

Head-Driven Phrase Structure Grammar

Head-Driven Phrase Structure Grammar (HPSG) is a constraint-based or declarative approach to linguistic knowledge, which analyses all descriptive levels (phonology, morphology, syntax, semantics, pragmatics) with feature value pairs, structure sharing, and relational constraints. In syntax it assumes that expressions have a single relatively simple constituent structure. This volume provides a state-of-the-art introduction to the framework. Various chapters discuss basic assumptions and formal foundations, describe the evolution of the framework, and go into the details of the main syntactic phenomena. Further chapters are devoted to non-syntactic levels of description. The book also considers related fields and research areas (gesture, sign languages, computational linguistics) and includes chapters comparing HPSG with other frameworks (Lexical Functional Grammar, Categorial Grammar, Construction Grammar, Dependency Grammar, and Minimalism)

Head-Driven Phrase Structure Grammar

Head-Driven Phrase Structure Grammar (HPSG) is a constraint-based or declarative approach to linguistic knowledge, which analyses all descriptive levels (phonology, morphology, syntax, semantics, pragmatics) with feature value pairs, structure sharing, and relational constraints. In syntax it assumes that expressions have a single relatively simple constituent structure. This volume provides a state-of-the-art introduction to the framework. Various chapters discuss basic assumptions and formal foundations, describe the evolution of the framework, and go into the details of the main syntactic phenomena. Further chapters are devoted to non-syntactic levels of description. The book also considers related fields and research areas (gesture, sign languages, computational linguistics) and includes chapters comparing HPSG with other frameworks (Lexical Functional Grammar, Categorial Grammar, Construction Grammar, Dependency Grammar, and Minimalism)