Page 70 - Designing Sociable Robots

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5 The Physical Robot

The design task is to build a physical robot that encourages humans to treat it as if it were
a young socially aware creature. The robot should therefore have an appealing infant-like
appearance so that humans naturally fall into this mode of interaction. The robot must have
a natural and intuitive interface (with respect to its inputs and outputs) so that a human can
interact with it using natural communication channels. This enables the robot to both read
and send human-like social cues. Finally, the robot must have sufficient sensory, motor, and
computational resources for real-time performance during dynamic social interactions with
people.

5.1 Robot Aesthetics and Physicality

When designing robots that interact socially with people, the aesthetics of the robot should
be carefully considered. The robot’s physical appearance, its manner of movement, and its
manner of expression convey personality traits to the person who interacts with it. This
fundamentally influences the manner in which people engage the robot.

Youthful and appealing It will be quite a while before we are able to build autonomous
humanoids that rival the social competence of human adults. For this reason, Kismet
is designed to have an infant-like appearance of a fanciful robotic creature. Note that
the human is a critical part of the environment, so evoking appropriate behaviors from
the human is essential for this project. The key set of features that evoke nurturing re-
sponses of human adults (see figure 5.1) has been studied across many different cultures
(Eibl-Eibesfeldt, 1972), and these features have been explicitly incorporated into Kismet’s
design (Breazeal & Foerst, 1999). Other issues such as physical size and stature also mat-
ter. For instance, when people are standing they look down to Kismet and when they are
seated they can engage the robot at eye level. As a result, people tend to intuitively treat
Kismet as a very young creature and modify their behavior in characteristic baby-directed
ways. As argued in chapter 3, the same characteristics could be used to benefit the robot by
simplifying the perceptual challenges it faces when behaving in the physical world. It also
allows the robot to participate in interesting social interactions that are well-matched to the
robot’s level of competence.

Believable versus realistic Along a similar vein, the design should minimize factors that
could detract from a natural infant-caretaker interaction. Ironically, humans are particularly
sensitive (in a negative way) to systems that try to imitate humans but inevitably fall short.
Humans have strong implicit assumptions regarding the nature of human-like interactions,
and they are disturbed when interacting with a system that violates these assumptions (Cole,
1998). For this reason, I consciously decided to not make the robot look human. Instead

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