RT Journal Article SR Electronic T1 Prospective mixed methods study of online and offline social networks and the development of sexual agency in adolescence: the Social Networks and Agency Project (SNAP) protocol JF BMJ Open JO BMJ Open FD British Medical Journal Publishing Group SP e024329 DO 10.1136/bmjopen-2018-024329 VO 9 IS 5 A1 Megan S C Lim A1 Spring Cooper A1 Larissa Lewis A1 Kath Albury A1 Kon Shing Kenneth Chung A1 Deborah Bateson A1 Melissa Kang A1 S Rachel Skinner YR 2019 UL http://bmjopen.bmj.com/content/9/5/e024329.abstract AB Introduction Social media may play a role in adolescent sexual development. The limited research on social media use and sexual development has found both positive and negative influences. The focus of this study is on sexual agency: a positive sexual outcome. This paper describes the protocol for the Social Networks and Agency Project (SNAP) study which aims to examine the relationship between online and offline social networks and the development of healthy relationships and sexual agency in adolescence.Methods and analysis The SNAP study is a mixed methods interdisciplinary longitudinal study. Over an 18-month period, adolescents aged 15–17 years at recruitment complete three questionnaires (including demographics, sexual behaviour, sexual agency and social networks); three in-depth interviews; and fortnightly online diaries describing their sexual behaviour and snapshots of their social networks that week. Longitudinal analyses will be used to describe changes in sexual behaviour and experiences over time, sexual agency, social media use, and social network patterns. Social network analysis will be used to capture relational data from which we will be able to construct sociograms from the respondent’s perspective. Interview data will be analysed both in relation to emergent themes (deploying a grounded theory approach), and from a cross-disciplinary perspective. This mixed method analysis will allow for comparisons across quantitative and qualitative data, for consistency and differences, and will enhance the robustness of data interpretation and conclusions drawn, as multiple data sources are triangulated.Ethics and dissemination Ethical approval was granted by the University of Sydney Human Research Ethics Committee and the Family Planning New South Wales Ethics Committee. The study will provide comprehensive, prospective information on the social and sexual development of adolescents in the age of social media and findings will be disseminated through conference presentations and peer-reviewed publications.