Computing Perspective in Dialogue - Computational Linguistics and Talking Robots - page 189

10. Computing Perspective in Dialogue
A computational reconstruction of dialogue requires not only an analysis of
language expressions, but of utterances . In DBS, an utterance is defined as (i)
a propositional content and (ii) a cluster of four pointers called STAR. 1 The
STAR serves to anchor a content to the interpretation's parameter values of
S pace, T ime, A gent, and R ecipient. The STAR also provides the referents for
a certain kind of sign in natural language, namely the indexical .
Three different STARs are used to code three different perspectives on con-
tent: (i) the STAR-0 for coding the agent's perspective on nonlanguage content
resulting from recording current recognition and action, (ii) the STAR-1 for
coding the speaker's perspective on content underlying language production,
and (iii) the STAR-2 for coding the hearer's perspective on content resulting
from language interpretation. It is shown that the computation of these per-
spectives by means of DBS inferences is completely mechanical.
10.1 Agent's STAR-0 Perspective on Current Content
Indexicals raise the question of whether they should be classified as function
or as content words. In DBS, all words with their own reference mechanism,
i.e., symbol, indexical, and name, are treated as content words ( Autoseman-
tika ). All words which do not have their own reference mechanism, such as
determiners, prepositions, conjunctions, and auxiliaries, are treated as func-
tion words ( Synsemantika ).
English, like many other natural languages, has five fundamental indexical
pointers which are used to refer to (1) the speaker, as in I and we ,(2)the
hearer, as in you , (3) an agent or object other than the speaker and the hearer,
as in he, she, it, they, and this , (4) the present moment, as in now ,and(5)
the present location, as in here . The referent of an indexical is determined
by the origin of the sign containing it, represented as the STAR of the sign's
utterance.
1 FoCL'99, Sect. 5.3.