IRIT/SAMOVA

• Analysis
• Modeling
• Audiovisual Content Structuring
• Natural Language Processing
  • Lexical semantics of predicative forms
  • Text Syntax and Semantics
  • Question-Answering
  • Assisted Correction of Grammatical, Stylistic and Textual Errors
• Applications

Context

Lexical semantics consists in:

1. assigning several levels of meaning to lexical terms and
2. defining semantic relations, either paradigmatic or functional, between lexical entries.

To handle this huge problem, addressed since the early stages of the antiquity, our contribution concentrates on predicative forms, verbs and prepositions, with a conceptual and operational perspective.

Overview

Via the VOLEM and PREPNET projects, we developed an approach to specifying the semantics of those predicative forms based on the lexical conceptual structure (LCS). Besides mere descriptions of lexical entries, our aim was to investigate, in the spirit of Beth Levin and many others, the intimate relations between semantics and syntax. We also investigated the composition effects between verbs and prepositions, within a decompositional approach to meaning.

For verbs, we investigated their argumentation structure; we then defined a relatively fined-grained set of thematic roles appropriate for our applications and then assigned thematic grids to verbs. We investigated some forms of polysemy and metaphor formation. Finally, we investigated methods to extend the LCS so that it is sufficiently expressive.

For prepositions, we proposed a language-independent semantic classification and an architecture to structure prepositions according to their meaning. We investigated compositionality aspects, in other terms how verbs and preposition (or PPs) combine. For example, in a number of cases, e.g. prepositions denoting instrumentality and many other adjuncts, the representation of prepositions has wider scope over the verb. Finally we investigated linguistic models to account for the syntax and the semantics of prepositions where, in fact, many other marks can be used instead such as: postpositions, affixes, verbs, etc. e.g.  in Indian languages, Thai, Malay and Filipino. A particular effort has been devoted to prepositions and other marks dedicated to instrumentality.

Contributors

• Emmanuelle Cannesson
• Alda Mari
• Patrick Saint-Dizier (contact)

Main Publications

• P. Saint-Dizier The linguistic dimensions of prepositions and their use in NLP applications, Kluwer academic, 2006.
• Patrick Saint-Dizier.  Syntactic and Semantic Frames in PrepNet. in: International Joint Conference on Natural Language Processing (IJCNLP 2008), Hyderabad (Inde), janvier 2008. 
• Asanee Kawtrakul, Sudeshna Sarkar, Patrick Saint-Dizier. Introducing Instruments in the Generative Lexicon. International Workshop on Generative Approaches to the Lexicon (GL 2007), Paris, Pierrette Bouillon, Hidetoshi Kanzaki (Eds.), Presses Université de Genève, may 2007.
• Patrick Saint-Dizier. PrepNet: a Multilingual Lexical Description of Prepositions. in: Language Resources and Evaluation Conference (LREC 2006), Gènes, European Language Resources Association (ELRA),  2006