The increase in the 1970's state aid to independent colleges and the doubling of interest groups representing independent colleges in the states (39 state associations by 1978) are examined, and a demonstrable relationship is found between these facts. It is argued that the chief factor motivating states to act on behalf of independent colleges is influence from interest groups representing independent colleges at the state level and that the strength of interest groups affects the amount of aid appropriated to independent colleges. Interest group strength is measured in terms of the amount of money the group spends, the degree of internal unit within the organization, quality of leadership, skillful use of strategy, and the variety of tactics used to influence policy. Case studies of selected states offer a vehicle for evaluation of the relationship between policy output and interest group operations. A summary of the findings of a multivariate statistical study of interest group influence is presented. Factors describing group operations in the different states provide examples for action in other settings. Data tables show: average tuition in public and independent colleges from 1956 to 1975, in current and 1974 dollars; characteristics of private colleges contributing to quality and diversity (small enrollment, single-sex, predominantly black, selective, or highly-ranked); states without interest groups or in which groups were formed after passing aid legislation; and a profile of independent colleges in six unnamed states. A list of references is included. (Author/MSE)