The goal of this
research is to develop Animated Pedagogical Agents (APA) that can convey
clearly perceivable emotions through speech, facial expressions and body gestures.
In particular, the two studies reported in the thesis investigated the extent
to which modifications to the range of movement of 3 beat gestures, e.g., both
arms synchronous outward gesture, both arms synchronous forward gesture, and
upper body lean, and the agent ‘s gender
have significant effects on viewer’s perception of the
agent’s emotion in terms of valence and arousal. For each gesture the range of
movement was varied at 2 discrete levels. The stimuli of the studies were 8
12-seconds animation clips generated using a fractional factorial design; in
each clip an animated agent who speaks and gestures, gives a lecture segment on
binomial probability. 4 clips featured a female agent and 4 clips featured a male agent. In
the first study, which used a within-subject design and metric conjoint
analysis, 120 subjects were asked to watch the 8 stimuli clips and rank them
according to perceived valence and arousal (from highest to lowest). In the
second study, which used a between-subject design, 300 participants were
assigned to two groups of 150 subjects each. One group watched the 4 clips
featuring the male agent and one group watched the 4 clips featuring the female
agent. Each participant was asked to rate perceived valence and arousal for
each clip using a 7-point Likert scale. Results indicated that extending the
arms outwards and forwards as well as modifying the agent’s gender from male to
female increased perceived valence and arousal, whereas rotating the body
backwards increased only perceived valence.