Abstract
This thesis presents a collection of algorithms and data structures for the generation of
pronouns, anaphoric definite noun phrases, and one-anaphoric phrases. After a close
analysis of the particular kinds of referring expressions that appear in a particular
domain -that of cookery recipes -the thesis presents an appropriate ontology and a
corresponding representation language. This ontology is then integrated into a wider
framework for language generation as a whole, whereupon we show how the representation language can be successfully used to produce appropriate referring expressions for
a range of complex object types.
Amongst the more important ideas explored in the thesis are the following:
• We introduce the notion of a generalized physical object as a way of representing
singular entities, mass entities, and entities which are sets.
• We adopt the view that planning operators are essentially underspecified events,
and use this, in conjunction with a simple model of the hearer, to allow us to
determine the appropriate level of detail at which a given plan should be described.
• We make use of a discourse model that distinguishes local and global focus, and
is closely tied to a notion of discourse structure; and we introduce a notion of
DISCRIMINATORY POWER as a means to choosing the content of a referring expression.
• We present a model of the generation of referring expressions that makes use of
two levels of intermediate representation, and integrate this model with the use
of a linguistically- founded grammar for noun phrases.
The thesis ends by making some suggestions for further extensions to the work reported
here.
