Dialogue Acts Recognition - Man-Machine Dialogue: Design and Challenges - page 111

the prosodic indications, especially those concerning the intonation outline of
the utterance, and with the reference resolution results obtained in Chapter 6.
We also need the dialogue history with the semantic and pragmatic
representations calculated for the previous utterances, including the
identification of speech acts which were carried out. Finally, in the case of
multimodal dialogue, we also need a representation of the gestures carried
out, and in general a representation of the content carried by the modalities
which are processed to potentially allocate them a speech act which, due to
the nature of these modalities, is called a dialogue act rather than a speech
act. We will see that a gesture can indeed express an order, a query or an
assertion.
The result of the recognition of dialogue acts is the affectation of one or
more labels to the semantic content, these labels described the dialogue acts
which were carried out. As always, several alternative hypotheses can be
generated in the case of ambiguity and an underspecified representation in the
case of an impossibility to recognize a specific act. The pragmatic
representations thus obtained are the main parameters for the dialogue
management and the determination of the system's reaction, and they also
update the dialogue history.
This chapter is organized as follows: first, section 7.1 aims to describe the
nature of the dialogue acts; second, section 7.2 presents a few methods used in
MMD for their automatic identification, especially the processes implemented
in the multimodal dialogue, with the multimodal fusion process at the level of
dialogue acts (section 7.3).
7.1. Nature of dialogue acts
7.1.1. Definitions and phenomena
Austin [AUS 62] gives each utterance a locutionary act, which corresponds
to the generation of the utterance; an illocutionary act, that of querying, order,
etc.; and a perlocutionary act, which is the often the intentional generation of
certain effects on the beliefs and behaviors of the hearer. The term speech act
is used to describe the illocutionary acts. Searle [SEA 69] extends J. Austin's
categories and characterizes five types of main act based on the criteria such
as the sincerity condition or the direction of fit of the act, i.e., does it act on
the world or is it the opposite: assertives; directives, whose goal is to make the