"Much of the early work on poverty was highly quantitative:... It became increasingly clear, however, that while numbers are essential for policy and monitoring purposes, it is also important to understand people's perception of poverty and their mechanisms for coping with poverty and other situations of extreme economic and social stress." Researchers have recognized over the past few years that quantitative analysis of the incidence and trends in poverty, while essential for national economic development planning, must be complemented by qualitative methods that help planners and managers understand the cultural, social, political, and institutional context within which projects are designed and implemented. This report is based on a two-day workshop held in June 1998, where outside research specialists and World Bank staff discussed the importance of integrating these research methods. The participants reviewed experiences in the use of mixed-method approaches in Bank research and project design. This report is a result of those discussions. The report examines the need for integrated research approaches in social and economic development, presents case studies of integrated approaches in practice, and talks about lessons learned. Part I describes the evolution of interest in, and the potential benefits of integrated research, and, Part II presents case studies on how integrated approaches have been used in poverty analysis, education, health, and water supply and sanitation, while Part III discusses lessons learned with respect to the use of integrated approaches, and assesses the benefits that can be achieved.