Organizational change can be usefully conceptualized in terms of both its process and its content. Process refers to how change occurs. Content describes what actually changes in the organization. Theories and analyses of organizational change seek to explain why organizations change as well as what the consequences are of change. Empirical evidence on both questions is fragmentary and occasionally contradictory. Models that consider both process and content show the greatest potential for resolving this situation. Such models can be used to test social science theories as well as to evaluate programs of organizational change promulgated by consultants and practitioners. Basic organizational theory would be enhanced by greater attention to organizational change.