Opinions about what makes an effective middle school were elicited by this study in which 153 principals of exemplary middle schools and 35 national leaders of the middle school movement were queried. Questionnaires asked about the functions and characteristics of middle schools regarding (1) students, (2) teachers, (3) principals, (4) curriculum, and (5) facilities and organization. Data analyses included an examination of frequency of responses across the five categories for each item, examination of the mean item responses, intercorrelation and factor analysis of the items, and investigation of the responses aggregated within the five major areas. In addition to revealing opinions regarding each aspect of the middle school, overall findings indicated general agreement among principals and movement leaders within the five subcategories, although both groups responded within the context of their roles, movement leaders being concerned with promoting effective middle schools and principals being concerned with instructional leadership. In addition, principals and movement leaders did not support the national emphasis on training teachers specifically to work with early adolescents nor did they see the need for utilizing research findings in the classroom. All emphasized basic skills but stressed the need for maintaining a balanced curriculum. (Author/JM)