The research featured in this paper is part of the CORE-PACE Research Partnership, through which Policy Analysis for California Education (PACE) has partnered with the CORE districts to conduct research designed to support them in continuous improvement while simultaneously helping to improve policy and practice in California and nationwide. Through this partnership, PACE coordinates and executes research with partners from all of California's top universities, including Stanford University, the University of Southern California, and the University of California, Davis, in addition to engaging researchers from universities and research organizations nationwide. This policy brief and the accompanying report show that there is good reason to pursue the measurement of social-emotional learning (SEL) and school culture/climate (CC) as a way to better understand student and school performance. Using data from California's CORE districts--districts serving nearly one million students who have embraced systematic measurement of SEL and CC--this study shows that SEL and CC measures demonstrate reliability and validity, distinguish between schools, are related to other academic and non-academic measures, and also illuminate dimensions of student achievement that go beyond traditional indicators. This report also shows how the SEL and CC measures can be used to identify areas of improvement within schools, such as identifying subgroup gaps or differences in reports between various respondent groups. [For the accompanying report, "Using Surveys of Students' Social-Emotional Learning and School Climate for Accountability and Continuous Improvement," see ED574847.]