This study introduces a new set of weighting procedures for revealing the mediation mechanism in multi-level settings. These methods are illustrated through an investigation of whether the impact of a system-wide policy change on student outcomes is mediated by policy-induced peer composition change. When the policy changed not only…

The "Connected Mathematics Project" ("CMP)" is a problem-centered mathematics curriculum designed for all students in grades 6-8. Each grade level of the curriculum is a full-year program and covers numbers, algebra, geometry/measurement, probability, and statistics. The program seeks to make connections within mathematics,…