Even as higher education institutions offer more distance education courses, the attrition rate in these courses remains higher than face-to-face courses. One of the most cited reason by students who drop out of distance education classes is the lack of social interaction. Educational technology researchers have studied this problem from a sense of presence approach and have identified methods to create feelings of immersion and a sense that an individual is sharing virtual space with another individual. This study examines human-to-human social interaction as a function of first impressions and self-presentation tactics via avatars in a 3D, multi-user, virtual classroom. The focus of this study was to look at the influence first impressions and self-presentation tactics had on the development of a participant social network in a 3D, multiuser, virtual classroom. Data was gathered from the participants of a hybrid graduate course at a mid-size public university in the upper Midwest who met for five class sessions in a 3D multiuser, virtual classroom. The data was collected through surveys, participant observations and interviews. The results of gathered data indicate first impressions and self-presentation tactics do influence a virtual classroom's social network. The participants were aware of the importance of creating a good first impression via their avatar. Participants' first impression judgments influenced early social interaction in the class. Changes in participants' responses on a social network survey at the end of the course suggest that participants' self-presentation tactics had an impact. The findings of this study suggest that offering distance education courses in 3D multi-user, virtual worlds may be a partial solution to the high rate of attrition by providing an environment that encourages social interaction. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]