This data collection was assembled by Professor Constance Ewing Cook of Albion College. The study examines the attitudes of members of public interest groups regarding their reasons for joining the organizations, their activism, their level of satisfaction and plans for membership renewal, their knowledgeability about the group's choice of issues, and the degree of membership involvement in organizational issues. Also included are data regarding the gender, age, education, and occupation of the members. The universe for the sample included Michigan members of Common Cause, the American Civil Liberties Union, the League of Women Voters, and the Conservative Caucus. The data were collected by sending mail questionnaires to 250 randomly selected members of the above public interest groups.