This study explores mechanisms involved in small scale schooling and student engagement. Specifically, this study questions the validity of arguments for small scale schooling reforms that confound the promised effects of small scale schooling "structures" (such as smaller enrollments, schools-within-schools, and smaller class sizes) with the effects of the "school climates" assumed to follow from these structural changes. Data to address this issue was drawn from the Philadelphia Educational Longitudinal Study--one of the few publically-available datasets to include student-level measures of school-within-a-school participation and relative quality--and supplemented by school-level data from the National Center for Education Statistics' Common Core of Data. Regression analyses were designed to examine whether academic press and/or personalized teacher-student relationships--two aspects of school climate often associated with small scale schooling--mediate the relationships between small scale schooling structures and student engagement. The results suggest a pattern of widespread connections between small scale schooling structures and students' emotional engagement in school, but only a loose connection between these structures and students' behavioral engagement in school. Furthermore, school climate does, in fact, mediate many of the relationships between small scale schooling structures and emotional engagement; however, it does not fully mediate the relationship between small scale schooling structure and behavioral engagement. Findings relating student engagement to the quality of small learning communities relative to others in the same school suggest that comprehensive schools that are broken down into smaller within-school units may create a new mechanism for tracking students. Those who participate in relatively high quality small learning communities like school more and participate in more extracurricular activities/sports than students who participate in relatively low quality small learning communities or in no small learning community at all. These relationships are not mediated by school climate. Overall, the findings of this study suggest that the results of small scale schooling reforms are largely dependent on the school climates where they are instituted. [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.]