CALL FOR PAPERS

Parsing with Categorial Grammars
http://www.cs.toronto.edu/~tfowler/parsingwithcg/
July 20-24, 2009

organised as part of the European Summer School on Logic, Language and Information ESSLLI 2009 (http://esslli2009.labri.fr/), 20-31 July, 2009 in Bordeaux, France

Workshop Organisers:
Timothy Fowler and Gerald Penn, University of Toronto
{tfowler,gpenn}@cs.toronto.edu

Workshop Purpose:
Among computational linguists, there has been an enormous recent resurgence of interest in parsing with categorial grammars, both because of their extreme lexicalism and because of their well-defined connection to interpretable semantic terms. The recent work of Clarke, Curran and others on Combinatory Categorial Grammars, and of Moot, Baldridge and others on multimodal extensions of categorial grammar, in particular, has produced a collection of efficient and expressive parsing tools that have only just begun to make an impact on tasks such as the Pascal RTE challenge. As the CL community attempts to push the state of the art from mere syntactic annotation into parsers that actually allow for semantic inference, CG's position can only improve. At the same time, there is no shortage of variations on "categorial grammar," and there has not to date been a great deal of communication between the adherents of these various strands on their relative linguistic or semantical merits, nor on more technical concerns of algorithm design and numerical parametrization.

The aim of this workshop is to bring Ph.D. students and researchers in these various strands to share and assess their progress in the spirit of promoting categorial grammar's overall advancement. The intended focus of this workshop is the formal / computational side of CG research, with the intention of representing work across all variations of categorial grammar.

Workshop Format:
The workshop is part of ESSLLI and is open to all ESSLLI participants. It will consist of five 90-minute sessions held over five consecutive days in the first week of ESSLLI. There will be 2-3 slots for paper presentation and discussion per session. On the first day of the workshop, the organizers will present an introduction to the topic.

Invited Speakers:

• Johan Bos - Semantic Parsing with CCG in Real-World Applications

  Formal approaches in semantics have long been restricted to small or medium-sized fragments of natural language grammars. We argue that categorial grammars are very suitable for reaching wide-coverage grammars for semantic interpretation because they are lexicalised and have a transparant mapping between syntactic categories and semantic types. We substantiate this claim by taking Clark & Curran's statistical CCG parser (trained on Hockenmaier's CCGbank for English) and show how to build a principled syntax-semantic interface situated in Discourse Representation Theory. Despite the theoretical beauty of categorial grammars, not all is hunky-dory, and we will illustrate both the attractive and the less attractive aspects that arise in developing practical grammar formalisms. We will illustrate the resulting system for robust text interpretation in applications such as question answering and textual inference.

• Makoto Kanazawa - Datalog as a Uniform Framework for Parsing and Generation

  Various grammar formalisms with "context-free" derivations, including multiple context-free grammars, tree-adjoining grammars, and context-free tree grammars, can be straightforwardly represented by Datalog programs (i.e., logic programs without function symbols), if strings and trees are viewed as first-order structures or "databases". This is a generalization of the well-known definite clause grammar representation of context-free grammars and underlies CYK-style tabular parsing methods for these grammar formalisms. Moreover, when these grammars are coupled with Montague-style semantics, where meanings are represented by typed lambda terms, the problem of "tactical generation" or "surface realization" also reduces to Datalog query evaluation, provided that the lambda terms associated with the grammar rules are "almost linear". (The correctness of this reduction can be rigorously proved using a certain relaxation of second-order abstract categorial grammars, as shown by Kanazawa 2007.)

  The Datalog representation allows a unified view of algorithmic and complexity-theoretic issues surrounding parsing and generation, in abstraction from particular grammar formalisms. In this talk, I will look in some detail at the complexity-theoretic consequences of the Datalog representation on parsing and generation.

Workshop Programme Committee:

• Jason Baldridge (University of Texas at Austin)
• Stephen Clark (University of Cambridge)
• Timothy Fowler (University of Toronto)
• Julia Hockenmaier (University of Illinois at Urbana-Champaign)
• Richard Moot (LABRI)
• Glyn Morrill (Universitat Politècnica de Catalunya)
• Gerald Penn (University of Toronto)
• Mati Pentus (Moscow State University)
• Sylvain Pogodalla (LORIA)
• Yury Savateev (Moscow State University)
• Mark Steedman (University of Edinburgh)

Schedule:
Day 1

• Opening Session
• Invited Speaker: Johan Bos - Semantic Parsing with CCG in Real-World Applications

Local Arrangements:
All workshop participants including the presenters will be required to register for ESSLLI. The registration fee for authors presenting a paper will correspond to the early student/workshop speaker registration fee. Moreover, a number of additional fee waiver grants will be made available by the organizing committee on a competitive basis and workshop participants are eligible to apply for those.

There will be no reimbursement for travel costs and accommodation. Workshop speakers who have difficulty in finding funding should contact the local organizing committee to ask for the possibilities for a grant.

Further Information:
About the workshop: http://www.cs.toronto.edu/~tfowler/parsingwithcg/
About ESSLLI: http://esslli2009.labri.fr