elektronická verzia publikácie - FIIT STU - Slovenská technická ...

268 Selected Studies on Software and Information Systems
two-way; energy is moved backward from task goals to moves which directly lead to their
achievement, from there to moves which enable those moves, etc. Simultaneously in
the forward direction, energy is pushed into moves which can be immediately performed
given the conversation state and relational model, from there to moves which are enabled
by those moves, etc. In this way, REA's planner achieves task goals, conversational moves
obey logical preconditions, while moves expected to cause face threat to the user are deferred,
and topics are introduced gradually and coherently.
Figure 9-6. REA’s conversational moves in the activation network.
Although REA's relational modeling is relatively simple, and could engage only in a system-initiative
dialogue it produced interesting results. In evaluation, 4 experiments were
conducted, TASK vs. SOCIAL conditions crossed with EMBODIED vs. PHONE conditions.
In the TASK conditions (i.e. TASK+EMBODIED and TASK+PHONE) only taskoriented
dialogue moves were used, in the SOCIAL conditions identical task-oriented dialogue
moves along with social dialogue were used. In the EMBODIED conditions full
embodiment capabilities as described earlier were employed, in the PHONE conditions
only 3D renderings of apartments were shown and the agent conversed with subjects over
phone. For the purpose of the experiment, REA speech recognition was controlled by
a wizard-of-oz setup. Interestingly, only a single positive result was achieved, namely that
some evidence was found that small talk can lead to an increase trust. In this case however,
it was observed only for one group of users (extroverts) and in one medium (face-toface),
while it was hypothesized that it may be due to other reasons (e.g. inherent impulsivity
of extroverts). Other than that, the EMBODIED conditions clearly demonstrated that
REA's visual was very cold and uninviting, and her nonverbal behavior was insufficient.
Subjects generally preferred to conduct small talk with her over phone, while preferring
task-only talk face-to-face. Finally, the system-initiative approach was unable to carry on
with user-initiated social dialogue moves, and subjects simply believed that REA has