This study examined the social networks of college students and how such networks affect student commitment and persistence. The study's theoretical framework was based on application of the social network paradigm to Tinto's Student Integration Model, in which a student's initial commitment is modified over time as a result of the student's integration into the campus community. Freshmen enrolled for the spring 1993 semester responded (322 of 379) to the First-Year Experiences Survey, which involved identifying students with whom they frequently spoke and the dimensions on which they related to these students. Results were compared with enrollment data for the fall 1993 semester to identify students returning for their sophomore year. The largest effect on persistence was associated with the number of nominations received from other students, and this factor operated indirectly through enhanced social integration, institutional commitment, and intention. Overall, students with broader, well-connected networks were more likely to persist, whereas students with a higher proportion of ties falling within their social peer group were less likely to persist. (Contains 52 references.) (DB)