By conducting a large scale survey of elementary schools across California serving similarly challenged low-income student populations, a collaborative research team (EdSource, Stanford University, U.C. Berkeley, and American Institutes for Research) sought to find which current K-5 practices and policies are most strongly correlated with high achievement. The study's surveys focused on concrete and actionable practices and policies at the school level, but also gathered teacher and principal reports about district and classroom practices. Specifically, this study surveyed teachers and principals at California elementary schools in the 25th to 35th percentile band of the School Characteristics Index (serving high proportions of low-income students), then analyzed their survey results against the school's Academic Performance Index score for 2005.