Recent Developments in Computational Semantics in Applications

Seminar in Computational Linguistics
Lecturer: PD Dr. Valia Kordoni (kordoni@coli.uni-sb.de)
Place: Building C7 2, Konferenzraum 2.11
Time: Mo 16-18
Start: 23.04.2007
Appropriate for: Diplom, B.Sc., M.Sc.
Office hour: Thursday 15-16 (OR per arrangement via email)

Course Description

In this seminar we will discuss how semantics used in broad-coverage computational grammars can be linked to real applications.

The last decades have seen considerable progress and increasing interest in Computational Semantics (CS). Several semantic formalisms have been successfully implemented and integrated in large-scale NLP systems. At the same time, there is an increasing tendency for different approaches to CS to converge.

We will use a suitable semantic formalism to introduce the central issues of CS and to outline the ideas and insights behind the implementations. After discussing the derivation of expressions of such formalisms by appropriate syntax-semantics interfaces we focus on the integration of CS formalisms in real-life applications and their evaluation. We will illustrate the discussion with reference to the Open Source DELPH-IN grammars and resources for analysis and generation.

COURSE OUTLINE

Introduction to the field of Computational Semantics
- Motivation of CS systems: efficient handling of ambiguity by underspecified representations
- Central issues of CS (in particular, scope, ellipsis, anaphora and their interaction)
Syntax-Semantics Interface
- Efficient derivation of semantic representations
- Portability of CS modules to different systems
Formalisms in real life
- CS components of large-scale, large-coverage grammars
- CS for QA systems, Information Retrieval, Information Management, and Hyperlinking
- CS for hybrid (deep and shallow) processing
- Evaluation of and translatability between CS systems

Course functions in the COLI study programs

Elective course for M.Sc., B.Sc. and Diplom; CL and LT

Teaching Material

Meeting of 23.04.2007: Introduction of the topic.

Meeting of 30.04.2007: Distribution of topics for student presentations and seminar papers.

Meeting of 07.05.2007: Overview of the topic (VK).

Meeting of 14.05.2007: Glue Semantics (Peter Backes -- Peter's slides):

Ash Asudeh and Richard Crouch. 2002a. Glue Semantics for HPSG. In Frank Van Eynde, Lars Hellan and Dorothee Beermann (eds.) Proceedings 8th International Conference on Head-Driven Phrase Structure Grammar, 1-19, CSLI Publications, ISSN 1535-1793.
Mary Dalrymple, John Lamping, Fernando C. N. Pereira, and Vijay Saraswat. 2002. Linear Logic for Meaning Assembly. This is a revised version of the (overview) paper in Proc. of the Workshop on Computational Logic for Natural Language Processing, Edinburgh, UK. 1995.

Meeting of 21.05.2007: The Constraint Language for Lambda Structures (CLLS) (Lu Zhang -- Lu's slides):

Markus Egg, Alexander Koller, and Joachim Niehren. 2001. The Constraint Language for Lambda Structures. Journal of Logic, Language, and Information 10, 457-485.
Markus Egg, Joachim Niehren, Peter Ruhrberg, and Feiyu Xu. 1998. Constraints over Lambda Structures in Semantic Underspecification, Proceedings of ACL/COLING 98, 353-359.

Meeting of 28.05.2007: No Meeting (Pfingstmontag).

Meeting of 04.06.2007: Minimal Recursion Semantics (MRS) (Kostadin Cholakov -- Kostadin's slides):

Ann Copestake, Alex Lascarides and Dan Flickinger. 2001. An Algebra for Semantic Construction in Constraint-based Grammars. In: Proceedings of the 39th Annual Meeting of the Association for Computational Linguistics (ACL 2001), Toulouse, France.
Copestake, Ann, Dan Flickinger, Carl Pollard, and Ivan A. Sag. 2006. Minimal Recursion Semantics: an Introduction. Research on Language and Computation 3.4: 281--332.

Meeting of 11.06.2007: Discourse Representation Theory (DRT) (Michael Wirth -- Michael's slides):

Reyle, Uwe. 1993. Dealing with Ambiguities by Underspecification: Construction, Representation and Deduction. Journal of Semantics 10: 123-179.

Meeting of 18.06.2007: Jerry Hobbs and Stuart Shieber. 1987. An algorithm for generating quantifier scopings. Computational Linguistics, 13(1-2):47-63, January-June 1987. (Valia Kordoni).

Meeting of 25.06.2007: No Meeting (ACL 2007 in Prague).

Meeting of 02.07.2007: Semantics-to-Ontologies Mapping (Jana Besser -- Jana's slides).

Meeting of 09.07.2007: No Meeting (DFKI Opening in Berlin).

Meeting of 16.07.2007: MRS -> CLLS (Michaela Regneri -- Michaela's slides):

Ruth Fuchss, Alexander Koller, Joachim Niehren, and Stefan Thater. 2004. Minimal Recursion Semantics as Dominance Constraints: Translation, Evaluation, and Analysis. Proceedings of the 42nd ACL, Barcelona.
Alexander Koller and Stefan Thater. 2005. The Evolution of Dominance Constraint Solvers. Proceedings of the ACL-05 Workshop on Software, Ann Arbor.
Markus Egg and Katrin Erk. 2002. A compositional account of VP ellipsis. In Frank Van Eynde, Lars Hellan and Dorothee Beermann (eds.) Proceedings 8th International Conference on Head-Driven Phrase Structure Grammar, 162-179, CSLI Publications, ISSN 1535-1793.

References

Indicative bibliography.

Language of instruction

English

Course certificate

Presentation + seminar paper.

Credit points

Presentation and seminar paper: M.Sc. und B.Sc.: 7 Credits; Diplom 4 Credits Only presentation: M.Sc. und B.Sc.: 4 Credits; Diplom: 2 Credits

Valia Kordoni

Last modified: Mon Apr 28 14:43:54 CEST 2008