David Beaver, Stanford University

Title: Centering in OT

Abstract:

Centering (Grosz, Joshi & Weinstein 83) is a simple theory which has been used to explain phenomena of discourse coherence, inference by conversational participants, and anaphora resolution. Optimality Theory (\dibot) provides a formal framework for reasoning about combinations of linearly ranked linguistic constraints (Prince & Smolensky 93). While this framework has been extraordinarily influential in phonology, it has only recently started to make inroads into syntax, semantics and pragmatics. In this paper, I will present a restatement of Centering in Optimality Theory.

I will demonstrate the application of the reformulated theory with respect to anaphora resolution, In particular, I will show that with one choice of rankings, the OT forumlation is descriptively equivalent with regard to text interpretation to the widely used Centering algorithm proposed by Brennan, Friedman and Pollard (1987). However, the OT version is declarative, and can be used for generation as well as interpretation, as well as being applicable to rank texts as well as individual sentences. I argue that the reformulation opens up new research directions and offers a novel way to approach the wider goals of Centering Theory, placing it within an integrated model of discourse processing and conversational inference.