Page 170 - Socially Intelligent Agents Creating Relationships with Computers and Robots

Designing Sociable Machines 153

critical part of the environment, so evoking appropriate behaviors from the hu-
man is essential for this project. Kismet should have an appealing appearance
and a natural interface that encourages humans to interact with Kismet as if it
were a young, socially aware creature. If successful, humans will naturally and
unconsciously provide scaffolding interactions. Furthermore, they will expect
the robot to behave at a competency-level of an infant-like creature. This level
should be commensurate with the robot’s perceptual, mechanical, and compu-
tational limitations.
Great care has been taken in designing Kismet’s physical appearance, its
sensory apparatus, its mechanical specification, and its observable behavior
(motor acts and vocal acts) to establish a robot-human relationship that adheres
to the infant-caregiver metaphor. Following the baby-scheme of Eibl-Eiblsfeldt
[8], Kismet’s appearance encourages people to treat it as if it were a very young
child or infant. Kismet has been given a child-like voice and it babbles in its
own characteristic manner.
Given Kismet’s youthful appearance, we have found that people use many
of the same behaviors that are characteristic of interacting with infants. As a
result, they present a simplified class of stimuli to the robot’s sensors, which
makes our perceptual task more manageable without having to explicitly in-
struct people in how to engage the robot. For instance, we have found that
people intuitively slow down and exaggerate their behavior when playing with
Kismet, which simplifies the robot’s perceptual task. Female subjects are will-
ing to use exaggerated prosody when talking to Kismet, characteristic of moth-
erese. Both male and female subjects tend to sit directly in front of and close
to Kismet, facing it the majority of the time. When engaging Kismet in proto-
dialogue, they tend to slow down, use shorter phrases, and wait longer for
Kismet’s response. Some subjects use exaggerated facial expressions.
Along a similar vein, the design should minimize factors that could detract
from a natural infant-caretaker interaction. Ironically, humans are particu-
larly 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 [6]. For this reason, we consciously
decided to not make the robot look human.

Readable Social Cues. As with human infants, Kismet should send social
signals to the human caregiver that provide the human with feedback of its in-
ternal state. This allows the human to better predict what the robot is likely
to do and to shape their responses accordingly. Kismet does this by means of
expressive behavior. It can communicate emotive state and social cues to a
human through facial expression, body posture, gaze direction, and voice. We
have found that the scientific basis for how emotion correlates to facial expres-