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06.06.2008 FLATLANDS 2008 1
Kakia Chatsiou Modern Greek Grammar fragment Implementation using XLE
GreekGramReporting on the progress of the implementation of a Modern Greek Grammar Fragment using the
XLE parser
Kakia [email protected]
Dept of Language and LinguisticsUniversity of Essex
Parts of this project have been funded with an ESRC Award PTA-2004-031-00112 , support which is gratefully acknowledged.
Previous versions of this report have been presented at the LangUE 2007 International Postgraduate Conference and the Language and Computation Day 2007, University of Essex.
Kakia Chatsiou Modern Greek Grammar fragment Implementation using XLE
06.06.2008 FLATLANDS 2008 2
Outline
• Introduction – Overview of the ParGram Project– Project Objectives– Participating Members– The XLE Platform– Grammar Architecture
• The GreekGram Project– Overview– Assumptions– Coverage– Demonstration– Future Development Directions
Kakia Chatsiou Modern Greek Grammar fragment Implementation using XLE
06.06.2008 FLATLANDS 2008 3
Outline
• Introduction – Overview of the ParGram Project– Project Objectives– Participating Members– The XLE Platform– Grammar Architecture
• The GreekGram Project– Overview– Assumptions– Coverage– Demonstration– Future Development Directions
Kakia Chatsiou Modern Greek Grammar fragment Implementation using XLE
06.06.2008 FLATLANDS 2008 4
An Overview of the ParGram Project
Project Objectives
• Broad coverage grammars– Inclusion of important and frequently occurring constructions– Linguistically motivated analyses
• Parallel and crosslinguistic development of grammars between the participating members– All grammars are guided by a common set of linguistic principles
and a commonly agreed upon set of grammatical analyses and features
– Identical treatment of core crosslinguistic phenomena
• Methods in grammar engineering– Common test methods and evaluation strategies– Balance between efficiency, performance, reliability and
maintainability across grammars
Kakia Chatsiou Modern Greek Grammar fragment Implementation using XLE
06.06.2008 FLATLANDS 2008 5
Participating Members
An Overview of the ParGram Project
PARC, CAChinese, English,
French
EssexGreek, Welsh
ManchesterArabic
OxfordMalagasy
DCU, IrelandChinese, English, French, German,
Japanese, Spanish
Fuji XEROXJapanese
Bergen, NorwayGeorgian, Norwegian, Tigrinya
Ho Chi MinchVietnamese
DebrecenHungarian
IMS, StuttgartGerman
KonstanzUrdu
Sabanci, IstanbulTurkish
Kakia Chatsiou Modern Greek Grammar fragment Implementation using XLE
06.06.2008 FLATLANDS 2008 6
An Overview of the ParGram Project
The Xerox Linguistics Environment (XLE) Platform
• Under current development at PARC (Palo Alto Research Center, USA)
• An implementation of the Lexical Functional Grammar (LFG) Formalism
• Implemented in C; works in Unix, Linux, MacOS. MS Windows version under development.
• Integrates a morphological analyser employing Finite State Technology
• Can be used for both parsing and generation• Includes tools for various grammar development activities (such
as analysing performance, test-suites)• The core technology used in the consumer search engine based
on natural language processing which is currently under development by
Kakia Chatsiou Modern Greek Grammar fragment Implementation using XLE
06.06.2008 FLATLANDS 2008 7
An Overview of the ParGram Project
• a Silicon Valley Company, currently building a transformative consumer search enginesearch engine based on natural language processing:– It is based on technologies that take advantage of the structure and
nuances of natural language– It offers an innovative approach to searching:
• It breaks the confines of keyword search queries using both keywords, short phrases and natural language
• Makes search more natural and intuitive• Aims at fundamentally changing how we search the web and at the same
time delivering higher quality results• currently searching Wikipedia with the help of FreeBase as the semantic
knowledge database
(source: http://www.powerset.com )
06.06.2008 FLATLANDS 2008 8
Kakia Chatsiou Modern Greek Grammar fragment Implementation using XLE
Search Engine Demo
06.06.2008 FLATLANDS 2008 9
Kakia Chatsiou Modern Greek Grammar fragment Implementation using XLE
Demo – sample queries
• Who is Indiana Jones?• Which are the films that Spielberg directed?• I am looking for Van Gogh’s paintings• Paintings by Van Gogh• Albums by westlige• Books by Charles Dickens
06.06.2008 FLATLANDS 2008 10
Kakia Chatsiou Modern Greek Grammar fragment Implementation using XLE
The XLE parser interface
Kakia Chatsiou Modern Greek Grammar fragment Implementation using XLE
06.06.2008 FLATLANDS 2008 11
An Overview of the ParGram Project
Basic Grammar Architecture
Other Finite State Tools
Tokenizer
Morpholo-gical
AnalyserFST
Lexicon(s)(Hand-written
OrAutomatically
Extracted)
LFG Grammar
(rules, templates)
Grammar Resources(parsing
and generating)
Kakia Chatsiou Modern Greek Grammar fragment Implementation using XLE
06.06.2008 FLATLANDS 2008 12
Outline
• Introduction – Overview of the ParGram Project– Project Objectives– Participating Members– The XLE Platform– Grammar Architecture
• The GreekGram Project– Overview– Assumptions– Coverage– Demonstration– Future Development Directions
Kakia Chatsiou Modern Greek Grammar fragment Implementation using XLE
06.06.2008 FLATLANDS 2008 13
The GreekGram Project
Overview
• A preliminary effort to develop a large-scale LFG computational Grammar for Modern Greek
• Shares the objectives and principles of similar ParGram projects (parallel and crosslinguistic; balancing of maintainability and achieving large coverage)
• Current main focus is on development of grammar rules and syntactic phenomena relevant to my thesis; the lexicon is kept as minimal as possible
Kakia Chatsiou Modern Greek Grammar fragment Implementation using XLE
06.06.2008 FLATLANDS 2008 14
The GreekGram Project
Assumptions
• Focus on syntax (but in such a way that the representations produced could serve as direct and useful input for incorporation into semantic interpretations)
• All four possible Modern Greek Word orders are treated as equally acceptable in terms of markedness and acceptability
• Modern Greek word Order is represented non-configurationally (Tzanidaki, 1996; Alexopoulou, 1999)
• No treatment of morphology (using the Morphological analyzer or some other Finite state tool) – there is a separate lexical entry for each form.
Kakia Chatsiou Modern Greek Grammar fragment Implementation using XLE
06.06.2008 FLATLANDS 2008 15
The GreekGram Project
Coverage
• All 4 possible word orders (irrespective of markedness)• Pro-drop character of the language• Subcategorisation frames of intransitive, transitive and
ditransitive verbs• Number, case and gender agreement within the NP or PP;
subject-verb agreement• Basic Relative Clause structure• Coordination of relative clauses• Some punctuation
Kakia Chatsiou Modern Greek Grammar fragment Implementation using XLE
06.06.2008 FLATLANDS 2008 16
The GreekGram Project
Demonstration
Kakia Chatsiou Modern Greek Grammar fragment Implementation using XLE
06.06.2008 FLATLANDS 2008 17
The GreekGram Project
Future Development Directions
• Account for a greater variety of verb subcategorisation frames
• Enrich the lexicon adding more lexical entries• Account for the morphology within the lexicon, using the
XFST (or other finite state tools)• Expand the coverage of the grammar to other constructions
such as interrogatives, imperatives and negation• …
06.06.2008 FLATLANDS 2008 18
Kakia Chatsiou Modern Greek Grammar fragment Implementation using XLE
Thank you!
For more information and updates on the progress of the project visit
http://privatewww.essex.ac.uk/~achats/projects/greekgram/index.html