Plan of the series

Todayís lecture

The Grosz / Sidner framework for studying salience and coherence

The Grosz & Sidner theory of discourse structure

Topic / `Focusingí effects in Linguistics and Psychology

Terminological caveat

Centering Theory (Grosz, Joshi and Weinstein, 1995)

Claims of the theory, I:
Entity coherence

Concepts and definitions, I

Concepts and Definitions,II:
The CB

The CB: Examples

Constraint 1

Claims of the theory, II: Local salience and pronominalization

Rule 1

Claims of the theory, III:
Preserving the ranking


Utterance classification

Utterance classification, II

Utterance classification, III

Rule 2

Summary of the claims

A parametric theory

Goals of this work

A corpus-based reassessment of the claims of Centering (Poesio et al, 2004)

The parameters of the theory

Utterance and Previous Utterance




The GNOME corpus

An example GNOME text

Information marked up in the GNOME corpus

Agreement on NE attributes

The GNOME annotation of NEs in XML format

The MATE/GNOME markup scheme for anaphoric information

Agreement results

The scripts

The Vanilla Instantiation

Utterance and CF statistics with the Vanilla instantiation

Constraint 1

An example of violation of
(Strong) C1

Rule 2 (BFP): Statistics

Rule 2: evaluation

Rule 1: statistics

Rule 1: Results

An example of violation of Rule 1 (GJW 95)

Another example:

An example of violation of
Rule 1 (GJW 95)




Ambiguity in anaphora: results of a small study

Explicit and implicit ambiguity

Other ways of setting the parameters

Effect of changes in the utterance parameters on Strong C1

Effect of changes in the utterance parameters on Strong C1

Effect of changes in utterance parameters on Rule 1 (GJW 95)

Effect on Rule 2

Effect of the utterance parameters

The tradeoff between Constraint 1 and Rule 1

Changing the Realization parameters

Constraint 1
(indirect realization, u=f)

Constraint 1
(indirect realization, u=s)

Effect of parameter changes on Strong C1 and Rule 1

A violation to Rule 1 caused by indirect realization

Rule 2 (BFP): Statistics (u=s)

Effect of the realization parameters

Ranking parameters


TheGFTHERELIN instantiation

Linear order

Strube and Hahn, 1999

A violation to Rule 1 with Strube-Hahn, but not GFTHERELIN

A violation to Rule 1 with GFTHERELIN, but not Strube-Hahn

Rule 2 (BFP): Statistics
(Strube-Hahn, u=s)

Ranking variants: a summary

Discussion, I:
Comparing Instantiations

Beyond Entity Coherence: Relations

A Hybrid view of coherence

CB Uniqueness?


Important caveat: corpus work vs. behavioral studies

Possible continuations

Global discourse structure

Example: the Grosz 1977 `tentí story (made up)

Example: the Grosz 1977 `tentí story

Arguments for global organization: Clark and Sengulís experiments

Clark and Sengulís experiments

Anderson, Garrod and Sanford (1983)

Anderson, Garrod and Sanford (1983)

Intentional structure

Intentional structure

The Focus Space Stack

The Focus Space Stack

Other formalizations of the global focus

The Poesio et al 2006 studies

Results: stack model, pronouns

Results: stack model, definite descriptions

Cache model, pronouns

Cache model, definite descriptions

Summary of results

Some lessons