Page 252 - Designing Sociable Robots

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Grand Challenges of Building Sociable Robots 233

I conceptualized Kismet’s behavior to be the product of interactions within and between
four separate levels.
Believable behavior Kismet exhibits compelling and life-like behavior. To promote this
quality of behavior, the issues of audience perception and of biasing the robot’s design
towards believability, simplicity, and caricature over forced realism were addressed. A set of
proto-social responses that are synthetic analogs of those believed to play an important role
in launching infants into social exchanges with their caregivers have been implemented.
From video recordings of subjects interacting with Kismet, people do appear to treat
Kismet as a very young, socially aware creature. They seem to treat the robot’s expressive
behaviors and vocalizations as meaningful responses to their own attempts at communi-
cation. The robot’s prosody has enough variability that they answer Kismet’s “questions,”
comment on Kismet’s “statements,” and react to Kismet’s “exclamations.” They ask Kismet
about its thoughts and feelings, how its day is going, and they share their own personal
experiences with the robot. These kinds of interactions are important to foster the social
development of human infants. They could also play an important role in Kismet’s social
development as well.

13.2 Infrastructure for Socially Situated Learning

In the above discussion, I have taken care to relate these issues to socially situated learning.
In previous work, my colleagues and I have posed these issues with respect to building
humanoid robots that can imitate people (Breazeal & Scassellati, 2002). I quickly recap
these issues below.
Knowing what’s important Determining what the robot should attend to is largely ad-
dressed by the design of the attention system. It is easy for people to direct Kismet’s
attention, as well as to confirm when the robot’s attention has been successfully mani-
pulated. People can also use their voice to arouse the robot through attentional bids. More
work needs to be done, but this provides a solid foundation.

Recognizing progress The robot is designed to have both internal mechanisms as well
as external mechanisms for recognizing progress. The change in Kismet’s internal state
(the satiation of its drives, or the return to a slightly positive affective state) could be
used as internal reinforcement signals for the robot. Other systems have used signals of
this type for operant as well as classical conditioning of robotic or animated characters
(Velasquez, 1998; Blumberg et al., 1996; Yoon et al., 2000). Kismet also has the ability
to extract progress measures from the environment, through socially communicated praise,