A taxonomy was devised for describing and classifying organizational characteristics that have set the pattern for the coordinating mechanisms in 41 states. The information assembled covers a period of years dating back to the beginnings of coordination in each state so that historic trends can be seen. The significant emerging trends are: (1) The number of states relying upon neither statutory nor voluntary organizations for interinstitutional cooperation markedly decreased, particularly during 1955-65 when demand for higher education showed its greatest growth and institutions became more complex. (2) The number of states relying upon voluntary associations to perform the coordinating function increased in 1960 but several were supplanted by other organizational forms (statutory in every case). (3) The number of states creating various forms of statutory coordinating agencies, boards, or commissions markedly increased after 1960. In 22 states, there was no significant change in the pattern of coordination from 1945 to 1965. Among most of the remaining 28 states, however, the trends seem to indicate an evolutionary movement from no coordination, to voluntary coordination, to a form of public regulatory coordination. (JS)