Because organizations constantly interact with their environments, they respond to environmental pressures through an adaptation process that matches environmental exigencies with organizational capabilities. Snunith Shoham conducted an empirical study of the ways in which six California public libraries responded to changes in available resources and the composition of the populations they served during the 1970s. The author discusses the various techniques the libraries employed to influence their environment and the internal changes they made to adjust to a changed environment. Finally, Shoham suggests that the library director determines the library's response to change, the services it will provide, and its future goals and direction.