The use of embodied agents, defined as visual human-like representations accompanying a computer interface, is becoming prevalent in applications ranging from educational software to advertisements. In the current work, we assimilate previous empirical studies which compare interfaces with visually embodied agents to interfaces without agents, both using an informal, descriptive technique based on experimental results (46 studies) as well as a formal statistical meta-analysis (25 studies). Results revealed significantly larger effect sizes when analyzing subjective responses (i.e., questionnaire ratings, interviews) than when analyzing behavioral responses such as task performance and memory. Furthermore, the effects of adding an agent to an interface are larger than the effects of animating an agent to behave more realistically. However, the overall effect sizes were quite small (e.g., across studies, adding a face to an interface only explains approximately 2.5% of the variance in results). We discuss the implications for both designers building interfaces as well as social scientists designing experiments to evaluate those interfaces.

This paper explores the relationship between display of feedback (public vs. private) and the basis for evaluation (present vs. absent) of that feedback. Using a controlled, laboratory setting, we employ a fundamentally social, interpersonal context (speed-dating). Two participants (one male and one female) receive real-time performance feedback about either only themselves (private) or about both participants (public). We measure participant perceptions of monitoring, conformity, and self-consciousness about themselves and their dating partner. We also assess perceptions of system invasiveness, system competence, and system support. Results reveal a consistent pattern of significant interaction between feedback display and basis for evaluation conditions. In each of these interactions, public feedback with an added, trivial, basis for evaluation creates significantly lower perception of monitoring, conformity, self-consciousness, and system invasiveness, than the other three conditions. Additionally there is a main effect for basis for evaluation with respect to system competence and supportiveness. In each case, the presence of a basis produces more positive assessments than its absence. The experiment shows that reactions to being monitored and evaluated do not differ strictly along the dimension of public vs. private; basis for evaluation of feedback functions as a mediator and thus co-determines participant attitudinal responses. We discuss the implications of this at several levels, and present a broader cultural explanation in terms of the theory of rationalization. We also discuss the issues around and functionality of linking laboratory settings to larger cultural contexts in this and related fields of inquiry.