2003 IMTA Proceedings - International Military Testing Association

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The pragmatic module : SDRT
The implementation of this module will constitute the biggest load of work.
As already said, SDRT is a theory that predicts how successive sentences of a text/dialogue
will be linked to each other. To be able to do so, a number of rules and axioms must be
specified beforehand about the “state of the world” for the problem at hand. Thus, this has to
do with making explicit in the program what is left implicit in the natural language because
the subjects have a mental picture about the state of the world. By means of this
complementary set of information, it is possible to determine what type of relationships links
the sentence under consideration to one or more of the former ones.
For example, take the sentences Β04, B05, and B06.
Β04 Interpr. : This is the person who had an accident with a Belgian bus six months ago.
Β05 Officer : Yes… ?
Β06 Interpr. : But he did not get his money yet.
After Β04, SDRT builds a “segmented discourse representation structure” (SDRS). The
Figure 3 below shows those SDRS in their standard graphical form. Each of the parts after a Π
constitutes an entity of information for “monotonic recursive structures” (MRS) which parts
that can be univocally determined in the sense that there are at least no contradictions with
what is already known. This is a notational gloss for a more precise, but less readable
representation.
Figure 3a. Example of rules about the “state of the world” for SDRT
How does SDRT works with these entities ? First, an expression like “this is the person
who..;” implies that the speaking party (here the interpreter) supposes that the listening party
(here the officer) knows who the “this person” is (the Kosovar who is complaining). This
assumption is a general axiom meaning. Moreover, in the given context, we can assume as
“normal” that, if the person is known by the Damage Control, there is a file about that person.
This is a contextual common sense rule.
If this type of information is available to SDRT, it can compute this complementary
information (π4c) and link it through a causal relation to the sentence π4; relationship which is
in this case “consequence by default” (Def-Cons).
45 th Annual Conference of the International Military Testing Association
Pensacola, Florida, 3-6 November 2003