There is a need for more guidance on how to implement community-based participatory research, particularly on the roles of community members, throughout the process. This article focuses on how a Steering Committee, composed of representatives from community-based organizations, a local health department, an integrated health care system, and academia from the University of Michigan, participated in the design and implementation of a children's asthma study in Detroit, Michigan: Community Action Against Asthma. In addition, this article focuses on the role of community members as data collectors, examining a variety of sophisticated data collection roles. A description and analysis of how community members shaped and participated in the project, the lessons learned, and recommendations for practitioners are also presented.