Page 244 - Designing Sociable Robots

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Social Constraints on Animate Vision 225

The youngest subject took the liberty of exploring different interaction ranges, however.
Over the course of about fifteen minutes he would alternately approach the robot to a normal
face-to-face distance, move very close to the robot (invading its personal space), and backing
away from the robot. Upon the first appearance of the calling response, the experimenter
queried the subject about the robot’s behavior. The subject interpreted the display as the
robot wanting to play, and he approached the robot. At the end of the subject’s investigation,
the experimenter queried him about the further interaction distances. The subject responded
that when he was further from Kismet, the robot would lean forward. He also noted that
the robot had a harder time looking at his face when he was farther back. In general, he
interpreted the leaning behavior as the robot’s attempt to initiate an exchange with him. I
have noticed from earlier interactions (with other people unfamiliar with the robot) that a
few people have not immediately understood this display as a calling behavior. The display
is flamboyant enough, however, to arouse their interest to approach the robot.

Inferring the Level of Engagement

People seem to have a very good sense of when the robot is interested in a particular
stimulus or not. By observing the robot’s visual behavior, people can infer the robot’s level
of engagement toward a particular stimulus and generally try to be accommodating. This
benefits the robot by bringing it into contact with the desired stimulus. I have already
discussed an aspect of this in chapter 6 with respect to directing the robot’s attention.
Sometimes, however, the robot requires a different stimulus than the one being presented.
For instance, the subject may be presenting the robot with a brightly colored toy, but the
robot is actively trying to satiate its social-drive and searching for something skin-toned.
As the subject tries to direct the robot’s attention to the toy, the motion is enough to have the
robot glance toward it (during the hold-gaze portion of the search behavior). Not being the
desired stimulus, however, the robot moves its head and eyes to look in another direction.
The subject often responds something akin to, “You don’t want this? Ok, how about this
toy?” as he/she attempts to get the robot interested in a different toy. Most likely the robot
settles its gaze on the person’s face fairly quickly. Noticing that the robot is more interested
in them than the toy, they will begin to engage the robot vocally.

12.8 Limitations and Extensions

The data from these interactions is encouraging, but more formal studies with a larger
number of subjects should be carried out. Whenever introducing a new person to Kismet,
there is typically a getting acquainted period of five to ten minutes. During this time, the
person gets a sense of the robot’s behavioral repertoire and its limitations. As they notice
“hiccups” in the interaction, they begin to more closely read the robot’s cues and adapt their