“…Thomas and Hrebenar (1992) likewise define an interest group as "any association of individuals, whether formally organized or not, that attempts to influence public policy" (p. 153). In a recent study of education interest groups, Sipple, Miskel, Matheney, and Kearney (1997) stress the importance of adopting a broad definition so that few assumptions are made about interest groups, their memberships, or their ideologies. For the purpose of this study, ideas from a number of scholars (e.g., Baumgartner & Leech, 1998;Hrebenar, 1997;Kollman, 1998;Thomas & Hrebenar, 1992) are combined to form the following broad definition: interest groups refer to membership organizations, advocacy organizations not accepting members, businesses, and other organizations or institutions, whether formally organized or not, that try to influence public policy.…”