Based on the recommendation of the First Things First Research and Evaluation National Advisory Panel, in September 2015 First Things First contracted with Child Trends, a national research organization, to conduct a comprehensive evaluation of Quality First. The evaluation serves as the first phase of a three-phase project. In this first phase, the goals were to provide a review and analysis of Quality First to inform implementation and continuous improvement of the initiative. Specifically, there were three goals of the Phase I study: Goal 1: Conduct a review of Quality First's conceptual framework and program design to understand the system's benefits and challenges from the perspective of participants, leadership, and other stakeholders. Goal 2: Assess the Quality First data system. Goal 3: Conduct a validation of the Quality First Rating Scale (1 to 5 stars) to examine if the rating is working as expected and whether it distinguishes between different levels of quality. Recognizing the diversity of Quality First program participants and stakeholders, the study sample included urban, rural, and tribal programs, as well as a variety of ECE program types including child care centers and homes. The study used mixed methods including surveys of stakeholders and Quality First participants, observations of program quality, focus groups, interviews, and document review to collect information from a variety of perspectives. (author abstract)