Semantic Analyses and Representations - Man-Machine Dialogue: Design and Challenges - page 90

consists of the identification of presuppositions. This is the implicit content
that can be deduced from the utterance's content, as a prior supposition:
“hello, I would like to change a reservation for an eight o'clock departure”
presupposes that the speaker has already made a reservation, and that this
reservation was made for a different departure time. In a less precise manner,
we can also suppose that the change only concerns the time, and not the
departure station or the arrival. In any case, an MMD system will find it
advantageous to identify these implicit contents to be able to react relevantly:
to find the previous reservation (and if it needs a name or a number for it, to
ask the user for it), to check the settings and potentially ask the user to
confirm that the time is the only thing that should be changed.
Finally, the identification of allusions this time relies on a fine
interpretation of linguistic hints or on broader contextual information than
that which is included in the utterance. In “only the seven o'clock train stops
in Valence”, one of the potential allusions can thus be through the use of
“only”, “it could be expected that other trains stop in Valence”. Various rules
and laws allow us to determine allusions: the law of informativity, which can
be applied in this example with “only”, the law of exhaustivity, which allows
us to infer “some trains do not stop in Valence” from “some trains stop in
Valence”, the law of understatements, which allows us to infer “none of the
trains for Palaiseau are very enjoyable” from “some trains for Palaiseau are
not very enjoyable”, or even the law of negation, of argumentative inversion,
etc. In general, the allusions can cover very different phenomena, as in “I
think I will take the plane”, which, uttered after a long dialogue in which the
user tried to reserve train tickets, can imply “none of your suggestions are
acceptable”, “you are inefficient” or even “I am fed up, I will stop talking
with you”. For the MMD, the challenge is to identify the allusions that are
closest to the semantic content, so as to take into account the linguistic
phenomena such as those caused by the use of “only” or “some”. For the
MMD in closed domain, the allusions which are less clear can be deduced
from the settings linked to the task, for example the difficulty in satisfying the
user due to the number of suggestions he/she has refused.
5.3.2. At the level of multimodal utterance
In a multimodal dialogue, the semantic representation of the oral utterance
is confronted with other semantic aspects, such as those carried by gestures,