The concepts of gangs as groups and of gang boundaries are compared using observation-narrative data and egocentric network data. Focusing on these groups and boundaries assists in illustrating, through argument, that participant observation and social network analysis are able to yield complementary perspectives on youth gangs and are therefore, not mutually exclusive, field-based research techniques. Participant observation is seen as an effective technique to gather systematic observations on people and places and systematic and impromptu interviews with gang youth, neighborhood residents, local police, business owners, and other stakeholders influenced by the youth gangs. A social network is a set of actors and a relation measured across those actors. Social network analysis assumes that network actors’ interactions create persistent social patterns of interaction that influence individual behavior. Compositional analyses of personal (egocentric) social networks of same-gang youth provide measures of peer influence processes beyond participant observation. Comparative analyses of opposite-gang adolescents’ egocentric networks indicate a wide overlap among inter-gang friends. References