The purpose of this CDC-funded project was to better understand how behavioral data were used in HIV prevention community planning, and use this knowledge to develop and evaluate tools for increasing the use of data in HIV prevention planning. HIV prevention community planning represents one of many efforts, in a variety of health and human service areas, to formulate plans and policies that are evidence-based and reflective of community input. The attention to evidence-based planning and the incorporation of community input both reflect desires for transparency and accountability in the planning and provision of services to address public needs. HIV prevention community planning represents just one example of the efforts to put these principles into action. Despite the history of other planning mechanisms which have tried to integrate grassroots input with research evidence, there are surprisingly few legacies in the literature from these efforts. Indeed, the published literature on these planning programs is very limited. While there is a huge research literature on judgment and decision making, there has been relatively little effort to integrate this with community-oriented planning efforts. This project represents a first step in this direction.