This dissertation focused on citizen advocacy groups as an intervention strategy for affecting change in the policy process. The analysis is of a specific intervention in school desegregation policy by a citizen advocacy group. The purpose of this research was to identify the conditions under which a citizen advocacy group can intervene; the constraints to a successful intervention; and the attributes of a successful intervention. The case study was of the Community Coalition for School Integration, a citizen advocacy group which existed in Portland, Oregon between 1977 and 1980. A multi-method approach was used. It involved fifty interviews with members of the Coalition, school administration, school board and the media. In addition, historical and document analysis of secondary data and extensive literature review was done. The theoretical framework guiding this research was Iannaccone's dissatisfaction theory of governance, DIS/ID/STO/OS. DIS is evidence of community changed dissatisfaction reflected in voting behavior leading next to incumbent school board member defeat (ID) followed within two years by involuntary superintendent turnover (STO) and outside succession (OS). Rothman's (1968) models of community organization practice were used to analyze the intervention of the Coalition. The findings do confirm the DIS/ID/STO/OS theory of governance, but also suggest that community intervention is an intervening variable between the stage of dissatisfaction and incumbent defeat. The analysis of the intervention identifies six conditions necessary for community intervention: timeliness of the issue, financial resources, leadership, organizational support, staff, and media coverage. The major constraints were the lack of trust between the policy-making body and the citizen advocacy groups, and the political environment of the community. Attributes of successful intervention were: focused advocacy, multiple intervention strategies, and permanency of the organization. The impact of the citizen advocacy group's intervention is discussed, as are recommendations for future research.