The representation of agents: a study of phenomena in virtual environments

There is an increasing need for a robust emotion state model in human computer interaction, especially when naturalistic input, such as facial expression, is used. Existing cognitive models of emotion provide a starting point, but they are dependent upon phenomena which occur in the physical environment. Virtual environments present the human with qualitatively different phenomena. We investigated subjective, multidimensional responses and objective, facial responses to a set of 20 different phenomena or stimuli. This set of stimuli included caricatures and anthropomorphic forms typically used to represent agents in human interfaces. The stimuli were presented both static and dynamic forms. Subjects rated the anthropomorphic forms as having a higher degree of agency and intelligence. A variety of other interesting results were found relating to complexity, anthropomorphism, movement, and culture of the subject. These findings indicate that a substantially different emotion state model will have to be developed for human computer interaction. The findings provide practical heuristics for the design of "social" or agent-based interfaces.