Coordination in system design requires an interplay between different roles. In this work, we identify five design team roles that pertain to the partitioning and coordination of distributed design team tasks. The proposed characterization is based on self-reported responsibilities and communication behaviors from 109 student designers in 22 teams at the conclusion of a semester-long design project. The self-reports capture both how team members viewed their own work as well as communication patterns between team members. We leverage two representations of this data. Through text analysis, we identify keywords describing team member roles and responsibilities. Social network analysis can further distinguish roles based on team communication behaviors. Cluster analysis on both types of data identifies groups of individuals with similar characteristics. The resulting five clusters capture common roles in system design teams that simultaneously capture the diverse responsibilities and communication patterns.