The Methods Core provides expertise, leadership and infrastructure to promote the quality of HIV research projects across all CHIPTS Cores. It is designed as a comprehensive resource for biostatistical expertise, training, consultation and technical support for HIV research, across CHIPTS collaborating institutions and in support of research and community partners. The specific aims of the Methods Core are: 1. Science: Fostering a productive research environment by developing innovative statistical methods and analysis strategies for complex research problems; 2. Science: Providing conventional methodological support to research projects on a routine basis as well as data management, information technology, and data security infrastructure; 3. Networking: Sponsoring a seminar and roundtable series to highlight innovative methodological and data management techniques, thereby increasing research and community partners'knowledge;as well as linking scientists to partners with complementary expertise; 4. Capacity Building: Recruiting and retaining high caliber investigators with methods expertise at Center collaborating institutions;and, 5. Capacity Building: Developing, publishing, and disseminating methods tools for analyzing and managing the complex issues raised by HIV data.