PNNL

Abstract

This study examined the effectiveness of enhancing humanagentinteraction through the use of nonverbal behaviors. Ataxonomy is described, which organizes nonverbal behaviorsinto functional categories and the manner in which they can beembodied (i.e. through gesture, posture, paralanguage, eyecontact and facial expression). Prototype computer characterswere created according to guidelines extracted from thetaxonomy and their efficacy was empirical evaluated. Theresults indicate that by including trusting nonverbal behaviors,the perceived credibility of a computer character was enhanced,although addition of trusting bodily nonverbal behaviorprovided little in addition to trusting facial nonverbal behavior.Perhaps more importantly, a character expressing non-trustingnonverbal behaviors was perceived to be the least credible of allcharacters examined (including a character that expressed nononverbal behavior). Participants that interacted with thispersona perceived the task to be more demanding, madesignificantly more errors, and rated their interaction lesspositively and more monotonous than those using trustingpersonas. They also rated this character to be less likable,accurate, and intelligent. Taken together, the results from thisstudy suggest that there may indeed be benefit to endowingcomputer characters with nonverbal trusting behaviors, as longas those behaviors are accurately and appropriately portrayed.Such behaviors may lead to a more trusting environment andpositive experience for users. Negative character behavior,however, such as non-trusting behavior, may squander theadvantages that embodiment brings.