LINGUIST List 6.229

Thu 16 Feb 1995

Confs: European ACL Tutorials 1995

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1. John Nerbonne, European ACL Tutorials 1995

Here is the tutorial schedule for EACL-95. All tutorials
will be held on Tues. March 28.

 EACL-95

 7th Conference of the European Chapter of the Association for
 Computational Linguistics

 March 27-31, 1995
 University College Dublin
 Belfield, Dublin, Ireland

Tutorials, Tues. 28 March
-------------------------

9:00 Registration

9:30-12:30 Martin Kay, Xerox PARC and Stanford

 "Theory and Implementation of Finite State Phonology, I"

*** The FSP tutorial is organized so that those competent in FSP
fundamentals may skip the morning session and therefore register only
for the afternoon (as a single session). Registration for just the
morning session would also be possible. ***

9:30-12:30 Alan Smeaton, Dublin City University

 "Natural Language Processing and Information Retrieval"

 2:00-5:00 Martin Kay, Xerox PARC and Stanford

 "Theory and Implementation of Finite State Phonology, II"

 2:00-5:00 Shalom Lappin, School for Oriental and African Languages,
 University of London

 "Computational Approaches to Ellipsis Resolution"

Registration information is available from the ftp file server:
(ftp://ftp.cs.columbia.edu/acl-l/Eacl95/registration.txt.Z).

 $ ftp ftp.cs.columbia.edu
 Name (cs.columbia.edu:pereira): anonymous
 Password: yournameaddress [not echoed]
 cd acl-l/Eacl95
 ftp) get registration.txt.Z
 ftp) quit
 $ uncompress registration.txt.Z

Abstracts for Tutorials:

1. Martin Kay "Theory and Implementation of Finite-State Phonology"

ABSTRACT: This two-part tutorial presents a set of mathematical and
computational tools for manipulating and reasoning about regular
languages and regular relations and argues that they provide a solid
basis for computational phonology. It shows in detail how this
framework applies to ordered sets of context-sensitive rewriting rules
and also to grammars in Koskenniemi's two-level formalism. This
analysis provides a common representation of phonological constraints
that supports efficient generation and recognition by a single
interpreter.
RECOMMENDED READING: Ronald M. Kaplan and Martin Kay "Regular Models
of Phonological Rule Systems" Computaional Linguistics 20(3), 1994,
331-378.

2. Alan Smeaton, "Natural Language Processing and Information Retrieval"

Abstract: The tutorial is aimed at an NLP audience who want to find
about a possible application area for NLP resources and techniques
... information retrieval.
 What is information retrieval ... functionality, including document
retrieval, filtering, and routing ... application areas, present and
perceived. Conventional approaches to IR ... it is essential to see
what other techniques have been used in IR to appreciate where NLP
can/cannot be of use .... indexing techniques, boolean retrieval,
vector space model, probabilistic modelling, term weighting and
relevance feedback, query expansion, ranking. Storage structures
... this will be *very* short, just touching on the engineering
problems of managing gigabytes of text.
 3 sections cover the guts of the NLP-IR intersection and will be
peppered with illustrative examples.
- Lexical resources/morphology in indexing by word senses, base forms,
 grammatical categories, stemming.
- Syntax in indexing and matching, phrase identification and
 extraction, phrase normalisation and matching
- Semantics in indexing and matching ... KR formalisms, examples of
 systems/prototypes which use higher-order NLP
Issues of scale ... examples and illustrations of NLP-based IR (IR
using NLP tools, techniques or resources) working on large scale
collections, examples from TREC.
 Research issues and trends ... this section will be a discussion,
led by me, on what I perceive as the directions in which the IR-NLP
intersection will head.

3. Shalom Lappin "Computational Approaches to Ellipsis"

ABSTRACT: The sentences in 1 illustrate three types of incomplete structures.
 1a. John read the paper before Bill did.
 b. Max gave flowers to Lucy, and chocolates too.
 c. No student arrived, except John.
1a is an instance of VP ellipsis, 1b is a case of "bare argument
ellipsis", and 1c contains an exception phrase fragment. I will
consider two possible approaches to developing a unified procedure for
interpreting these distinct kinds of incomplete constituents. The
first involves generating the semantic representation of an
appropriate property or relation for the elided constituent
fragment. The second attempts to reconstruct a syntactic
representation of a VP or sentence containing the fragment. I will
consider each approach in some detail, and argue that neither the
semantic nor the syntactic view can handle all three types of
incomplete constituent.
 I will provide motivation for the claim that VP ellipsis requires
syntactic reconstruction, and that it is, in fact, a species of
pseudo-gapping illustrated in 2.
 2. John gave flowers to Lucy before he did chocolates to Rosa.
On this view, reconstruction is a relation between an elided VP and an
equivalence class of lexically anchored syntactic structures which
correspond to an antecedent VP. All elements of the equivalence class
exhibit the same syntactic structure, but variation among
corresponding lexical anchors with respect to a restricted set of
specified features is possible. The syntactic structure of a (perhaps
partially) elided VP is reconstructed by identifying its elided head
with the head of an antecedent VP, and then specifying a
correspondence among the arguments and adjuncts of the antecedent head
on one hand and those of the elided head on the other. I discuss the
algorithm for VP ellipsis resolution presented in Lappin and McCord
(1990) and extended in McCord et al. as an implementation of this
analysis.
 I argue that, contrary to VP ellipsis, bare argument ellipsis must
be resolved by means of a semantic procedure for predicate
generation. I consider the higher-order unification analysis proposed
in Dalrymple et al. (1991) as a possible account of this procedure.
 Finally, I present arguments for treating an exception phrase
fragment not as an instance of ellipsis, but as a displaced NP
modifier. NP storage (Cooper (1993), Pereira (1990), and Pereira and
Pollock (1991)) provides a suitable device for expressing the
connection between a displaced exception phrase and the NP which it
modifies.
 The study of these three types of incomplete constituents
indicates that the interpretation of ellipsis and constituent
fragments is not a unified process. Each fragment type requires a
different reconstruction procedure which operates at a distinct level
of representation.
BACKGROUND READING
Dalrymple, M., S. Shieber, and F. Pereira (1991), "Ellipsis and
 Higher-Order Unification", Linguistics and Philosophy 14, pp. 399-452.
Fiengo, R. and R. May (1994), Indices and Identity, MIT Press,
 Cambridge, MA. Haik, I. (1987), "Bound Variables that Need to Be",
 Linguistics and Philosophy 11, pp. 503-530.
Hardt, D. (1993), Verb Phrase Ellipsis: Form, Meaning, and Processing,
 unpublished Ph.D. dissertation, University of Pennsylvania,
 Philadelphia, PA.
Lappin, S. (1993a), "The Syntactic Basis of Ellipsis Resolution" in
 S. Berman and A. Hestvik (eds.), Proceedings of the Stuttgart Ellipsis
 Workshop, Arbeitspapiere des Sonderforschungsbereichs 340, Bericht
 Nr. 29-1992, University of Stuttgart, Stuttgart.
Lappin, S. (1993b), "Ellipsis Resolution at S-Structure" in Amy
 Schafer (ed.), Proceedings of NELS 23, University of Massachusetts,
 Amherst, MA., pp. 255-269.
Lappin, S. and M. McCord (1990), "Anaphora Resolution in Slot
 Grammar", Computational Linguistics 16, pp. 197-212.
Pereira, F. (1990), "Categorial Semantics and Scoping", Computational
 Linguistics 16, pp. 1-10.
Reinhart, T. (1991), "Elliptic Conjunctions- Non-Quantificational QR"
 in A. Kasher (ed.), The Chomskyan Turn, Blackwell, Oxford, 360-384.
Sag, I. (1976), Deletion and Logical Form, unpublished
 Ph.D. dissertation, MIT, Cambridge, MA.
Webber, B. (1979), A Formal Approach to Discourse Anaphora, Garland
 Publishing Co., New York.
Williams, E. (1977), "Discourse and Logical Form", Linguistic Inquiry
 8, pp. 101-139.