ITRI-99-19
Rodger Kibble and  Richard Power

Using centering theory to plan coherent texts

We assume that the component propositions to be realised in a text are 
organised in a tree structure in which terminal nodes are elementary
propositions and non-terminal nodes represent discourse relations as defined 
by e.g., Rhetorical Structure Theory (RST, Mann and Thompson 1987).  
This structure only partially determines the linear order in which 
the propositions will be realised - in other words, any RST structure 
specifies a range of possible text plans.  We propose as an additional constraint that 
the generator should seek to maximise {\em continuity 
of reference} as determined by the rules and constraints of centering 
theory, and we argue that this enables us to select the most cohesive 
variants from a set of text plans.



Also published in Proc 12th Amsterdam Colloquium, Amsterdam, The Netherlands, pp. 187-192.