<?xml version="1.0" standalone="yes"?>
<Paper uid="P96-1036">
  <Title>Functional Centering</Title>
  <Section position="2" start_page="0" end_page="270" type="intro">
    <SectionTitle>
1 Introduction
</SectionTitle>
    <Paragraph position="0"> The centering model has evolved as a methodology for the description and explanation of the local coherence of discourse (Grosz et al., 1983; 1995), with focus on pronominal and nominal anaphora. Though several cross-linguistic studies have been carded out (cf. the enumeration in Grosz et al. (1995)), an almost canonical scheme for the ordering on the forward-looking centers has emerged, one that reflects well-known regularities of fixed word order languages such as English. With the exception of Walker et al. (1990; 1994) for Japanese, Turan (1995) for Turkish, Rambow (1993) for German and Cote (1996) for English, only grammatical roles are considered and the (partial) ordering in Table 11 is taken for granted.</Paragraph>
    <Paragraph position="2"> ~Table 1 contains the most explicit ordering of grammatical roles we are aware of and has been taken from Brennan et al. (1987). Often, the distinction between complements and adjuncts is collapsed into the category &amp;quot;others&amp;quot; (c.f., e.g., Grosz et al. (1995)).</Paragraph>
    <Paragraph position="3"> Our work on the resolution of anaphora (Strube &amp; Hahn, 1995; Hahn &amp; Strube, 1996) and textual ellipsis (Hahn et al., 1996), however, is based on German, a free word order language, in which grammatical role information is far less predictive for the organization of centers. Rather, for establishing proper referential relations, the functional information structure of the utterances becomes crucial (different perspectives on functional analysis are brought forward in Dane~ (1974b) and Dahl (1974)). We share the notion of functional information structure as developed by Dane~ (1974a). He distinguishes between two crucial dichotomies, viz. given information vs. new information (constituting the information structure of utterances) on the one hand, and theme vs. rheme on the other (constituting the thematic structure of utterances; cf. Halliday &amp; Hasan (1976, pp.325-6)). Dane~ refers to a definition given by Halliday (1967) to avoid the confusion likely to arise in the use of these terms: &amp;quot;\[...\] while given means what you were talking about (or what I was talking about before), theme means what I am talking about (now) \[...\]&amp;quot; Halliday (1967, p.212). Dane~ concludes that the distinction between given information and theme is justified, while the distinction between new information and rheme is not.</Paragraph>
    <Paragraph position="4"> Thus, we arrive at a trichotomy between given information, theme and rheme (the latter being equivalent to new information). We here subscribe to these considerations, too, and will return in Section 3 to these notions in order to rephrase them more explicitly by using the terminology of the centering model.</Paragraph>
    <Paragraph position="5"> In this paper, we intend to make two contributions to the centering approach. The first one, the introduction of functional notions of information structure in the centering model, is methodological in nature.</Paragraph>
    <Paragraph position="6"> The second one concerns an empirical issue in that we demonstrate how a functional model of centering can successfully be applied to the analysis of several forms of anaphoric text phenomena.</Paragraph>
    <Paragraph position="7"> At the methodological level, we develop arguments that (at least for free word order languages) grammatical role indicators should be replaced by functional  role patterns to more adequately account for the ordering of discourse entities in center lists. In Section 3 we elaborate on the particular information structure criteria underlying a function-based center ordering.</Paragraph>
    <Paragraph position="8"> We also make a second, even more general methodological claim for which we have gathered some preliminary, though still not conclusive evidence. Based on a re-evaluation of empirical arguments discussed in the literature on centering, we stipulate that exchanging grammatical by functional criteria is also a reasonable strategy for fixed word order languages.</Paragraph>
    <Paragraph position="9"> Grammatical role constraints can indeed be rephrased by functional ones, which is simply due to the fact that grammatical roles and the information structure patterns, as we define them, coincide in these kinds of languages. Hence, the proposal we make seems more general than the ones currently under discussion in that, given a functional framework, fixed and free word order languages can be accounted for by the same ordering principles. As a consequence, we argue against Walker et al.'s (1994, p.227) stipulation, which assumes that the C I ranking is the only parameter of the centering theory which is language-dependent. Instead, we claim that functional centering constraints for the C! ranking are possibly universal.</Paragraph>
    <Paragraph position="10"> The second major contribution of this paper is related to the unified treatment of specific text phenomena. It consists of an equally balanced treatment of intersentential (pro)nominal anaphora and textual ellipsis (also called functional or partial anaphora).</Paragraph>
    <Paragraph position="11"> The latter phenomenon (cf. the examples given in the next section), in particular, is usually only sketchily dealt with in the centering literature, e.g., by asserting that the entity in question &amp;quot;is realized but not directly realized&amp;quot; (Grosz et al., 1995, p.217). Furthermore, the distinction between those two kinds of realization is generally delegated to the underlying semantic theory. We will develop arguments how to locate elliptical discourse entities and resolve textual ellipsis properly at the center level. The ordering constraints we supply account for all of the above mentioned types of anaphora in a precise way, including (pro)nominal anaphora (Strube &amp; Hahn, 1995; Hahn &amp; Strube, 1996). This claim will be validated by a substantial body of empirical data (cf. Section 4).</Paragraph>
  </Section>
class="xml-element"></Paper>