Project Summary Joseph D. Tucker, an Associate Professor in the Division of Infectious Diseases at the University of North Carolina at Chapel Hill (UNC), submits this application for a K24 Mid-Career Award. Dr. Tucker is a nationally recognized thought leader on HIV testing and crowdsourcing. Crowdsourcing is the process of having a group of non-experts and experts develop a solution, then implement the solution in the community. In this application, he proposes to develop skills that will serve his future work in this significant area of research, including behavioral economics, participatory interventions, and strategies for effective leadership. Candidate: Dr. Tucker has been a highly productive HIV clinical researcher and has developed a substantial HIV research program in China. He has 208 peer-reviewed publications, including several research studies that have informed national and global policy. Dr. Tucker is PI on two NIAID R01 research grants and one D43 Global Infectious Diseases Training Grant. He is Chair of the Burroughs Wellcome Fund/American Society of Tropical Medicine and Hygiene Postdoctoral Fellowship Committee. As Director of the UNC-South China STD Research Training Center, Dr. Tucker has helped to build capacity for HIV and STD co-infection research and training in China. He has served as primary mentor for many new clinician investigators who have subsequently become successful independent HIV researchers. Mentoring Plan/Environment: This application will leverage the extensive training resources at UNC Project- China in Guangzhou, China and at UNC. In China, the UNC-South China STD Research Training Center and the SESH research team at Southern Medical University provide unique opportunities for research training. As founding Director of UNC Project-China, Dr. Tucker is well-positioned to mentor students, fellows, and junior faculty in China. In Chapel Hill, the UNC Center for AIDS Research, the North Carolina Translational and Clinical Science (NC TraCS), and several HIV training grants provide research training that Dr. Tucker has helped junior investigators join. As requests for mentoring have increased, Dr. Tucker proposes to receive formal and informal guidance to develop further as a mentor. Research Plan: The established research infrastructure Dr. Tucker and his collaborators have built in China provides a strong platform for mentored research. Five studies led by Dr. Tucker have demonstrated that crowdsourcing approaches are effective in developing sexual health messages for young men who have sex with men (YMSM). The proposed study will evaluate crowdsourcing approaches to enhance HIV prevention for YMSM. This will increase our understanding of differentiated HIV prevention services and provide rich opportunities for mentee research and training.