Joint Colloquium

The Department of Linguistics and the Department of Computer Science at The University of Arizona invite you to a colloquium presentation by
Speaker: John Hale
Johns Hopkins University
Topic: Quantifying Ambiguity Resolution with Information Theory
Date:Tuesday, March 25th, 2003
Time:11:00 AM
Place:Gould-Simpson Bldg., Room 701
Refreshments will be served in the 7th floor lobby at 10:30 AM


Ambiguities about grammatical category and syntactic structure permeate natural language. Explaining human comprehenders' performance in the face of such confusion has been called the central problem in sentence processing (Tabor & Tanenhaus, 2001). How is it that human sentence understanders are able to recognize combinatory relationships, from an infinite range of possibilities, to arrive at a meaningful interpretation of a sentence?

This talk argues that an answer lies in formalizing the idea that comprehenders search the space of grammatical analyses in a way constrained by the words they hear. Comprehenders are constantly engaged in ambiguity resolution, and the more ambiguity is resolved, the longer they take.

To make this intuition fully explicit, ambiguity resolution will be given a precise interpretation in terms of information theory. The general theory is tested using explicit grammar fragments that are probabilistic versions of Generalized Phrase Structure Grammars (Gazdar, Klein, Pullum & Sag 1985) and Minimalist Grammars (Stabler 1997). The theory will be shown to derive a range of well-documented processing phenomena including garden-path sentences, center-embedding, and the Accessibility (or Obliqueness) Hierarchy of relativized grammatical functions.

Gazdar, Gerald, Ewan Klein, Geoffrey Pullum and Ivan Sag (1985) Generalized Phrase Structure Grammar. Harvard University Press.
Stabler, Edward P., Jr. (1997) "Derivational Minimalism", in Logical Aspects of Computational Linguistics, ed. by Christian Retore. Springer-Verlag.
Tabor, Whitney and Michael K. Tanenhaus (2001) "Dynamical Systems for Sentence Processing", in Connectionist Psycholinguistics, ed. by Morten H. Christiansen and Nick Chater. Ablex.

ABOUT THE SPEAKER John Hale received his ScB in Cognitive Science and Computer Science from Brown University in 1998, his MA in Cognitive Science from Johns Hopkins University in 2000, and is currently completing his PhD dissertation in Cognitive Science at Johns Hopkins, under the direction of Paul Smolensky, Edward Stabler (UCLA) and Edward Gibson (MIT). He has published several journal articles and conference papers, and received the 2002 Jerrold J. Katz Young Scholar Award for his paper "The Information Conveyed by Words" at the 15th CUNY Conference on Human Sentence Processing. He describes his research as investigating "the formal character and mechanical use of linguistic information" in such areas as cognitive load in sentence processing, syntactic priming, inferring gender of named entities in very large corpora, parsing with extended finite-state transducers, and the investigation of grammar formalisms, including Optimality Theory.