This study explores the relationship between the structure of an existing social network and the structure of an emergent discussion-board network in an undergraduate university class. Thirty-one students were issued with laptop computers that remained in their possession for the duration of the semester. While using these machines, participants' email log files were collected directly from the University's email servers. The analysis compared structural attributes of actors evident in their social network with the emergent structural properties measured from interactions in a shared discussion board environment. A significant relationship was found between the existing social network structure and the emergent communication patterns, suggesting that existing relationships have a strong influence on subsequent computer-mediated communication. Additional matrices were used to control for gender, major and perceived computer efficacy, none of which had a significant effect.