According to developmental psychology, human development occurs in an identifiable sequence of stages. Appropriate experiences at each stage make development smoother and more rapid. Leadership can be roughly defined as the ability to structure events in a way that will take best advantage of developmental patterns. Members of organizations are affected not only by their own developmental experiences, but by their roles in the organization and by the effects of their interactions with other individuals in the organization who are also developing. Organizational leadership requires the maintenance, initiation, and integration of structure in the expectations and interactions of the organization's members. A model of organizational leadership based on developmental ideas was tested using the Nebraska Principals' Leadership Questionnaire. Teachers in three midwestern suburban school districts indicated their perceptions of their principals' developmental leadership behavior. These perceptions were compared to ratings of the principals' effectiveness provided by their superintendents and assistant superintendents. Principals judged more effective were found to have significantly higher developmental leadership qualities in their teachers' eyes. (Author/PGD)