This report expands on the work of an earlier National Research Council panel whose report, Understanding Violence Against Women, was published in 1996. The report is based on the presentations and deliberations of a workshop convened in January 2002, at the request of Congress, to develop a detailed research agenda on violence against women. While some of the research recommendations in the earlier report have been funded and carried out, the workshop demonstrated that important gaps remain. For example, prevalence and incidence data are still inadequate to measure trends or to reveal whether interventions being designed under federal programs are, in fact, working. Among its primary recommendations, the committee underscored the importance of strengthening the data and research infrastructure in this area, especially the need for better prevalence data and longitudinal data to determine the causes of violent victimization of women and the impact of interventions.