American educators and researchers have spent decades attempting to determine the most effective middle level school configuration. Although various models have been conceptualized in order to resolve one of our most extensive educational reform movements, a recent nationwide increase in K-8 schools suggest interested parties have accepted the K-8 concept for its favorable results as compared to middle schools. Some of the positives of the K-8 concept include: greater involvement of parents and staff, higher achievement, higher student self-esteem, and fewer incidents of student misconduct reflecting a more positive school climate. Other research, however, has shown that grade level organization does not directly correlate to higher achievement and that school climate, organizational values, and teacher attitudes are more significant in explaining school performance. The purpose of this dissertation was to investigate the inconsistencies of past middle level research and determine if K-8 school configurations outperform middle schools in California. Findings partially support the construct validity of the originally-proposed Heck and Marcoulides model (1996b) across K-8 and MS structures and, demonstrate that K-8s outperform MS at the 8th grade level. Moreover, the study identified educationally important aspects of teacher-perceived cultural variables and how these perceptions collectively and specifically impact school performance in K-8 schools but not in middle schools. In order to develop higher achieving middle level schools, school leaders are encouraged to (1) prioritize team building strategies to empower staff, bolster collegiality, and allow the principal to focus on school performance, (2) connect parents to the school via meetings and workshops designed to improve parental support at home, and (3) dedicate time and resources for teachers to participate in decision-making and to discuss best teaching practices with their peers. These recommendations may apply to most school settings regardless of configuration. One problem with the MS structure may be that staff members have less time to develop relationships with students and their parents compared to the K-8 structure. Further, disparity in school performance can be attributed mostly to teacher perception differences of the school climate, teacher attitudes, and organizational values. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]