(Georgia Institute of Technology, 2009-07-07)
Park, Sung Jun
A framework for understanding the social responses to virtual humans suggests that human-like characteristics (e.g., facial expressions, voice, expression of emotion) act as cues that lead a person to place the agent into the category "human" and thus, elicit social responses. Given this framework, this research was designed to answer two outstanding questions that had been raised in the research community (Moon&Nass, 2000): 1) If a virtual human has more human-like characteristics, will it elicit stronger social responses from people? 2) How do the human-like characteristics interact in terms of the strength of social responses? Two social psychological (social facilitation and politeness norm) experiments were conducted to answer these questions. The first experiment investigated whether virtual humans can evoke a social facilitation response and how strong that response is when participants are given different cognitive tasks (e.g., anagrams, mazes, modular arithmetic) that vary in difficulty. They did the tasks alone, in the company of another person, or in the company of a virtual human that varied in terms of features. The second experiment investigated whether people apply politeness norms to virtual humans. Participants were tutored and quizzed either by a virtual human tutor that varied in terms of features or a human tutor. Participants then evaluated the tutor's performance either directly by the tutor or indirectly via a paper and pencil questionnaire. Results indicate that virtual humans can produce social facilitation not only with facial appearance but also with voice recordings. In addition, performance in the presence of voice synced facial appearance seems to elicit stronger social facilitation (i.e., no statistical difference compared to performance in the human presence condition) than in the presence of voice only or face only. Similar findings were observed with the politeness norm experiment. Participants who evaluated their tutor directly reported the tutor's performance more favorably than participants who evaluated their tutor indirectly. In addition, this valence toward the voice synced facial appearance had no statistical difference compared to the valence toward the human tutor condition. The results suggest that designers of virtual humans should be mindful about the social nature of virtual humans.
(Georgia Institute of Technology, 2006-07-11)
Park, Sung Jun
When people do an easy task, and another person is nearby, they tend to do that task better than when they are alone. Conversely, when people do a hard task, and another person is nearby, they tend to do that task less well than when they are alone. This phenomenon is referred to in the social psychology literature as "social facilitation" (the name derives from the "good" side of the effect). Different theories have been proposed to explain this effect. The present study investigated whether people respond to a virtual human the same way they do to a real human. Participants were given different tasks to do that varied in difficulty. The tasks involved anagrams, mazes, modular arithmetic, and the Tower of Hanoi. They did the tasks either alone, in the company of another person, or in the company of a virtual human on a computer screen. As with a human, virtual humans produced the social facilitation effect: for easy tasks, performance in the virtual human condition was better than in the alone condition, and for difficult tasks, performance in the virtual human condition was worse than in the alone condition. Implications for the design of instructional systems as well as other systems involving human-computer interactions are discussed.