Federal policy makers and school leaders increasingly recognize middle school math as a turning point in students' academic success. An i3 scale-up grant allowed grant partners to conduct a large-scale implementation of PowerTeaching (PT), a research-based reform to increase student math achievement. In a mixed-methods study during the pilot phase of the project, eight schools' readiness for reform was explored. Teacher questionnaires; interviews with project managers, school leaders, and teachers; classroom observations; and school evaluation forms were used to describe school characteristics that affected variability in initial implementation of the PT model. A cluster analysis demonstrated the relative importance of multiple factors in defining clusters of schools with varying levels of implementation. Classroom observations of teachers' instructional practices and classroom structure as well as teacher beliefs about team learning were found to be statistically significant. Fundamental to a reform's successful implementation are a stable network of strong players, and an ability by the school leader to point the organization in one direction. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]