A record type theoretic approach to information state update in
dialogue -- is this pragmatics?

For several years the research group at our Dialogue Systems Lab has
been involved in the development of the information state update
approach to the building of dialogue systems and in particular Issue
based dialogue management developed in Staffan Larsson's PhD thesis
and based on Jonathan Ginzburg's gameboard approach to dialogue,
focussing on the notion of questions (or issues) under discussion.
Larsson's computational approach to information state updates involves
a large collection of update rules which fire when certain conditions
in the information state are met in a regime determined by a general
control algorithm.  An utterance by a dialogue participant will in
general unleash a whole chain of such updates and part of the power of
the approach lies in the fact that we can define very general update
rules which have small effects on the information state and which are
not necessarily linked to any particular form of utterance.  It gives
us a much finer grain on update rules than thinking in terms of single
monolithic updates associated with speaker utterances.

In this paper we will show how notions of record and record type in
type theory can be used to formulate update rules without relying on
these aspects of Prolog.  This allows us to give an abstract
characterisation of update rules independent of programming language
which points to a general theory of updates as well as the possibility
of implementation in any programming language. The tools we are using
can also be used in an account of compositional semantics and this
points to the possibility of an integrated formal theory of
information state update and compositional semantics.

In the light of this we will consider the question of whether dialogue
management belongs to pragmatics and in general what the relationship between
semantics, dialogue management and pragmatics might be.