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Robot in Society: A Question of Interface 19

Finally, the structure of instructional situations is iterative: the instructor demonstrates,
the student performs, and then the instructor demonstrates again, often exaggerating or fo-
cusing on aspects of the task that were not performed successfully. The ability to take turns
lends significant structure to the learning episode. The instructor continually modifies the
way he/she performs the task, perhaps exaggerating those aspects that the student performed
inadequately, in an effort to refine the student’s subsequent performance. By repeatedly re-
sponding to the same social cues that initially allowed the learner to understand and identify
the salient aspects of the scene, the learner can incrementally refine its approximation of
the actions of the instructor.
For the reasons discussed above, many social-learning abilities have been implemented on
Kismet. These include the ability to direct the robot’s attention to establish shared reference,
the ability for the robot to recognize expressive feedback such as praise and prohibition, the
ability to give expressive feedback to the human, and the ability to take turns to structure
the learning episodes. Chapter 3 illustrates strong parallels in how human caregivers assist
their infant’s learning through similar social interactions.

2.3 Embodied Systems That Interact with Humans

Before I launch into the presentation of my work with Kismet, I will summarize some
related work. These diverse implementations overlap a variety of issues and challenges that
my colleagues and I have had to overcome in building Kismet.
There are a number of systems from different fields of research that are designed to
interact with people. Many of these systems target different application domains such as
computer interfaces, Web agents, synthetic characters for entertainment, or robots for phys-
ical labor. In general, these systems can be either embodied (the human interacts with a
robot or an animated avatar) or disembodied (the human interacts through speech or text
entered at a keyboard). The embodied systems have the advantage of sending para-linguistic
communication signals to a person, such as gesture, facial expression, intonation, gaze di-
rection, or body posture. These embodied and expressive cues can be used to complement or
enhance the agent’s message. At times, para-linguistic cues carry the message on their own,
such as emotive facial expressions or gestures. Cassell (1999b) presents a good overview
of how embodiment can be used by avatars to enhance conversational discourse (there are,
however, a number of systems that interact with people without using natural language).
Further, these embodied systems must also address the issue of sensing the human, often
focusing on perceiving the human’s embodied social cues. Hence, the perceptual problem
for these systems is more challenging than that of disembodied systems. In this section I
summarize a few of the embodied efforts, as they are the most closely related to Kismet.