Aim of this tutorial :

  Today, robust parsing is changing rapidly from tagging to chunking and clause bracketing. And partial parsing is becoming less and less partial, with computational properties which allow a good integration into industrial contexts, where linear complexity is a prerequisite : robust parsers are able to process raw linguistic material at a constant and foreseeable rate with foreseeable results.

  This tutorial is designed for PhD. students and researchers in NLP. The expected prerequisites are basic knowledge on parsing and tagging.

Downloading the documents :

• Slides of the Course (pdf full screen: 200 Kb, ppt.zip : 100 Kb, pdf to be printed : 70 Kb)
• Main References and Links (html)
• Practical Guidelines (html)
• Assessment Form (html)
• Submitted (and rejected) paper : "A linear algorithm for chunk linking" (paper in pdf, reviewers' comments)

Tutorial outline :

Session 1 : Course (3h)        (slides of the course)

• Introduction :
2 meanings of parsing : parsing with formal grammars versus robust parsing
• Standard operations in robust parsing :
• part-of-speech tagging
• function of tagging : giving a part-of-speech tag to every word
for shallow parsing on raw material
or for replacing morpho-lexical analysis before syntactic analysis
• an explicit process, but no explicit expected structures
• resources :
extracting probabilities from hand-tagged corpora
   (for instance : Church 1988 and 1993, Merialdo 1994)
or extracting symbolic rules from hand-tagged corpora (Brill tagger)
or manually writing symbolic rules (Xerox Grenoble, GREYC Caen)
• the importance of the tagset :
for contextual deductions,
and to measure performance
• different ways to articulate lexica and contextual resources
• the tagging process : triggering rules on tokens
• linear complexity, constant and foreseeable rate
• the beginning of a way of renewal in parsing strategies
• chunking
• the concept of chunk (Abney 1991, Church 1988)
• a prosodic segment
• a non recursive constituent
• functions of chunking : delimiting and typing chunks
• lexical resources : beginnings, endings and separators of chunks
• the chunking process : as in tagging, triggering rules on tokens
• chunking after tagging ?  or tagging and chunking together ?
• why tagging is easier and more accurate inside typed chunks
• grammatical words => beginning of a chunk, and type of the chunk
• the type of the chunk constrains the word categories
• linking chunks
• with an algorithm of linear complexity (Vergne and Giguet)
• clause bracketing and computing chunk main functions inside a clause
• the work done in Xerox Grenoble (Aït-Moktar and Chanod 1997)
• clause bracketing before chunking (Ejerhed 1996)
• Shared properties, and differences in robust parsing
• non recursive representations of constituent structures
• imply a hierarchy of constituents of different types :
token, chunk, clause, sentence, paragraph, ...
• and are a "comeback" of dependency representations
• implementations
• implementations based on statistical models (for instance :

            Church 1988, Merialdo 1991 and 1995, Briscoe and Carrol 1993, Rajman 1995)
• or finite state transducers (for instance : Ejerhed 1996, Abney 1996,

           Aït-Moktar and Chanod 1997)
• or rules and engine (GREYC Caen)
• Two technologies to implement symbolic rules
• Finite-State Transducers (FST)
• Engine and rules
• Typical applications
• Comparing robust parsing with formal grammar parsing
• Introduction to the practical

Session 2 : Practical (3h)            (practical guidelines)

• Chunking English :
• executing a very simple chunker for English
• modifying rules
• Changing natural language :
• making a chunker for French
• making a chunker for another language
• Linking 2 chunks : the subject noun chunk to the verb chunk
• Changing scale of the computed unit : clause bracketing
• The genericity of the GREYC engine
• the language dimension
• the scale dimension

Tutorial speakers :

Main References and Links

Some references for a preliminary insight into the topic :

Abney S. (1995). "Chunks and Dependencies: Bringing Processing Evidence to Bear on Syntax". In: Computational Linguistics and the Foundations of Linguistic Theory. CSLI. pp. 145-164.
http://www.sfs.nphil.uni-tuebingen.de/~abney/Abney_91i.ps.gz

Abney S. (1996b). "Partial Parsing via Finite-State Cascades". In Proceedings of the ESSLLI '96 Robust Parsing Workshop.
http://www.sfs.nphil.uni-tuebingen.de/~abney/96h.ps.gz

Aït-Mokhtar S. and Chanod J.-P. (1997). "Incremental Finite-State Parsing". In Proceedings of ANLP'97, Washington, pp.72-79.
http://www.xrce.xerox.com/publis/mltt/mltt-97-01.ps

Brill E. (1992). "A simple rule-based part-of-speech tagger". In Proceedings of the Third Conference on Applied Natural Language Processing, Trento. ACL.

Church K. and Mercer R. (1993). "Introduction of the special issue of Computational Linguistics Using large corpora". Computational Linguistics, volume 19, number 1, pp.1-24.

Computational Linguistics (1993). "Special issue on Using large corpora". Volume 19, number 1 and 2.

Ejerhed E. (1996). "Finite state segmentation of discourse into clauses". In Proceedings of ECAI'96 Workshop Extended finite state models of language, A. Kornai (Ed.) pp.24-33. http://www.kornai.com/ECAI/ejerhed.html

Giguet E., Vergne J. (1997). "From Part-of-Speech Tagging to Memory-based Deep Syntactic Analysis". In Proceedings of the International Workshop on Parsing Technologies (IWPT'97), MIT, Boston, Massachussets.
https://giguete.users.greyc.fr/iwpt97/GiguetIwpt97.pdf

Giguet E. (1998). "Méthode pour l'analyse automatique de structures formelles sur documents multilingues". Ph.D thesis, Université de Caen.
https://giguete.users.greyc.fr/these/

Grefenstette G. (1996). "Light Parsing as Finite-State Filtering". ECAI'96 workshop on "Extended finite state models of language". Aug. 11-12, Budapest. http://www.xrce.xerox.com/publis/mltt/mltt-96-12.ps

Vergne J. and Giguet E. (1998).  "Regards Théoriques sur le Tagging". Cinquième conférence annuelle : Le Traitement Automatique des Langues Naturelles, TALN'98, Paris, pp. 22-31.
https://lucasn01.users.greyc.fr/JacquesVergne/VergneGiguetTaln98.pdf