The vitality of socio-technical networks, like online communities and social networks, is predominantly dependent upon active member participation. In most socio-technical networks a minority of members participate more than others and thus play key roles that sustain the value of the network. The overarching objective of this study was to extend the understanding of how to better facilitate socio-technical networks through examining the emergence and evolution of key role players in such networks. To accomplish this goal an exploratory case study approach was chosen, involving an in-depth, longitudinal examination of a single socio-technical network investigating the key roles of content contributors, opinion leaders, and boundary spanners. Log data gathered through the socio-technical network platform over a period of two years were analyzed to identify network members who played key roles, study their actions and interactions in the system from their first day of membership, develop predictive models for each key role based on the findings, and finally test the potential of these models for predicting which new members will become valuable members in the network. The study discovered that key role players start playing the key roles almost immediately after joining the socio-technical network, thus making it difficult to predict who will play key roles. However, a minority of members play key roles over a longer period of time, and the study found that is possible to a certain extent to predict who will become such long-term key role players. It was also established that it was relatively common for members of the socio-technical network to play multiple key roles, both over time and simultaneously, which led to developing a composite role framework for future studies of member role composition, distribution, and evolution in socio-technical networks. [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.]