Thesis advisor: Laura M. O'Dwyer / The purpose of this study was to inform future policy regarding school leadership practices through examining the relationship between reported decision making at the school level and student achievement. The study utilized a mixed methods design, and examined three main components. The first component involved a qualitative analysis of 14 countries' school leadership polices, as described in country background reports submitted to the Organization for Economic Cooperation and Development (OECD). The second component used hierarchical linear modeling (HLM) to examine the relationship between principal reported school decision making and student achievement in mathematics and reading on the Program for International Student Assessment (PISA) in the same 14 countries. The final component of this study connected the results from the policy analysis to the results of the HLM analysis to determine if there were patterns between a country's policies and the relationship between school-level decision making and student achievement. The study found that out of 14 countries included in the analysis, six countries were identified as having polices that were highly decentralized, three countries had policies that were highly centralized and five countries had policies that were somewhere in between the two extremes. The quantitative results showed that school-level decision making variables were limited in their utility as predictors of student achievement. Finally, an examination of the combined qualitative and quantitative results did not reveal any obvious patterns. However, the findings did highlight the importance of context in examining countries' policies and the relationship between leadership practices in the form of school decision making and student achievement. / Thesis (PhD) — Boston College, 2011. / Submitted to: Boston College. Lynch School of Education. / Discipline: Educational Research, Measurement, and Evaluation.