Centering: A Framework for Modelling the Local Coherence of Discourse,

Abstract

This paper concerns relationships among focus of attention, choice of referring expression, and perceived coherence of utterances within a discourse segment. It presents a framework and initial theory of centering intended to model the local component of attentional state. The paper examines interactions between local coherence and choice of referring expressions; it argues that differences in coherence correspond in part to the inference demands made by different types of referring expressions, given a particular attentional state. It demonstrates that the attentional state properties modeled by centering can account for these differences. PrefaceOur original paper (Grosz, Joshi, and Weinstein 1983) on centering claimed that certain entities mentioned in an utterance were more central than others and that this property imposed constraints on a speaker's use of different types of referring expressions. Centering was proposed as a model that accounted for this phenomenon. We argued that the coherence of discourse was affected by the compatibility between centering properties of an utterance and choice of referring expression. Subsequently, we revised and expanded the ideas presented therein. We defined various centering constructs and proposed two centering rules in terms of these constructs. A draft manuscript describing this elaborated centering framework and presenting some initial theoretical claims has been in wide circulation since 1986. This draft (Grosz, Joshi, and Weinstein 1986) has led to a number of papers by others on this topic and has been extensively cited, but has never been published. 1We have been urged to publish the more detailed description of the centering framework and theory proposed in Grosz, Joshi, and Weinstein (1986) so that an official version would be archivally available. The task of completing and revising this draft became more daunting as time passed and more and more papers appeared on centering. Many of these papers proposed extensions to or revisions of the theory and attempted to answer questions posed in Grosz, Joshi, and Weinstein (1986). It has become ever more clear that it would be useful to have a "definitive" statement of

An Incremental Discourse Parser Architecture

“…The second claim of VT extends the classical Centering Theory (CT) [6] at global level. As defined, centering is a theory of local coherence.…”

“…2 displays the three layers for two co-referencing REs). Let's notice that the composition of the projects and evokes relations yields the realises relation of centering [6]. As such, the world of REs can be seen as a simplification of the overall dynamic model of language interpretation, where we retain only REs and representations emerged from them.…”

“…As defined, centering is a theory of local coherence. CT defines a set of transition types for discourse [6], [1]: CONTINUATION which is easier to process than RETAINING, which is easier than SMOOTH SHIFTING, which is easier than ABRUPT SHIFTING. In [3] a smoothness index was introduced to compare different discourse structures and interpretations.…”

Where to place inaccessible subjects in Dutch: The role of definiteness and animacy

“…Grosz et al 1995). At the other end of the scale, non-specific indefinite NPs mark nontopical information, and hence denote inaccessible referents.…”

La portée de la comparaison, de la métaphore et de la métonymie sur la continuité référentielle en moyen français

“…Givón, 1983, Grosz, 1995et Gundel, 1993. En effet, si l'on suppose que l'énoncé se continue ainsi : « le bon homme glissa et il tomba sur les genoux de la dame », selon la continuité thématique et les règles valentiello-référentielles, on serait face à une situation référentielle qui suggèrerait que le référent « bon homme » est celui repris par le pronom personnel il.…”