California's Race to the Top-Early Learning Challenge (RTT-ELC) grant provided funding for the development of a locally driven Quality Rating and Improvement System (QRIS) or set of systems as well as an independent evaluation to validate the rating approach and assess outcomes associated with participation in the system. In January 2014, the California Department of Education (CDE) contracted with American Institutes for Research (AIR) and its partners at the RAND Corporation; Survey Research Management; and Allen, Shea & Associates to conduct the evaluation. The first year's validation results were presented in the half-term report (http://www.cde.ca.gov/sp/cd/rt/documents/airhalftermreport.pdf). This final comprehensive report highlights key findings from the half-term report (see chapter 2) and presents additional results related to the implementation of the system, quality improvement (QI) supports provided through the system, program quality and children's developmental outcomes, and perceptions of quality and the rating system. (author abstract)