SOCIALIZING CONSISTENCY - Human-Computer Interaction and Management Information Systems: Foundations - page 366

Designing Emotions as Dimensions: Manipulating Voice Settings to Create Feelings
Another way to conceive of emotions is in terms of two dimensions: valence (positive/negative)
and arousal (excited/calm). All of the basic emotions can be laid out along these dimensions (Lang,
1995). For example, happiness would be on the highly positive side of valence and slightly higher
than middle level on arousal. Using these dimensions makes setting voice emotion cues a relatively
simple task. For example, the more on the excited end of the arousal dimension, the higher the
voice's pitch should be and the wider its pitch range; also the voice should have wider volume
range and faster word speed (Nass and Brave, 2005). The more positive the valence dimension, the
higher the pitch and wider the pitch range should be; also the voice should have greater intensity
and more upward than downward inflections. Such guidelines provide a concrete basis upon which
to tweak synthetic voice settings to make voices more emotionally consistent with the words they
are speaking.
ONTOLOGY: IS IT (PRESENTED AS) A MAN OR A MACHINE?
Given the findings described in this chapter so far, the general conclusion could be that, from a
social perspective, embodied interfaces are treated as humans. Users respond to computer-based
voices and faces as if they exhibit very human characteristics such as personality, gender, ethnicity,
and emotion. Users further expect that the computer voice will be socially consistent on all of these
dimensions, much as they expect consistency from other humans. These findings appear regardless
of whether the embodied interface seems almost human (e.g., employs an actual human voice) or
seems distinctly non-human (e.g., employs an unambiguously synthetic voice).
Humans and machines are not equivalent, however, and it seems unlikely that users would
completely overlook this fact, particularly when obvious indications of machinehood are present.
When machines sound and look exactly like humans, it would be impossible for users to treat them
any other way (as the user would be unaware of whether they were interacting with a human or
a machine). However when machines give clear indications that they are machines, it seems unlikely
that people would treat them as equivalent to humans (one need only look at popular science fic-
tion to see that machines are often ascribed second-class citizenship, e.g., Asimov, 1991). From
a social perspective, this could be seen as humans and machines occupying distinct social classes,
much as humans of different ethnicity may occupy distinct social classes.
If this is true, we should expect to see a preference for consistency within these social cate-
gories: Any object that reminds one of a machine should consistently sound, look, and behave like
a machine, while any object that reminds one of a person should consistently sound, look, and behave
like a person. To investigate this conjecture, an experiment was conducted (Nass and Brave, 2005).
Saying “I”
Self-reference—thinking and talking in terms of “I”—is arguably the most human of human
actions (Descartes, 1999). Use of self-reference (i.e., the first person) therefore presented a perfect
way to test whether consistency in humanness is important to users. An experiment with a telephone-
based auction was conducted. Participants were first directed to a Web site. Upon registering, they
were given a scenario in which they were about to graduate and move to another city, and must
furnish their new apartments. This scenario was chosen because it was potentially relevant to all
of the participants, regardless of their gender and personal interests. Participants were then given a