Coalitions vary in their structure and in their funding sources. They can be "formal or informal; permanent (dedicated to a complex, long-term agenda) or temporary (formed for the achievement of a single task or goal); they may be ... staffed independently or collectively" (Advocacy Institute, 1990, p. 3). Most coalitions are informal, requiring members to contribute time, professional help, or clerical services. This informality minimizes power struggles and jurisdictional disputes. Coalitions vary in how much members have in common: some are homogenous, while others bring together "truly strange bedfellows" (Schlozman & Tierney, 1986, p. 48).