As part of a recent study, researchers from the RAND Corporation--together with analysts at MetrixIQ and the University of Cincinnati's Institute for Policy Research--worked with stakeholders in Cincinnati who were seeking to expand preschool access and quality in their city. Key study questions included: How many children already have access to high-quality preschool; should an expanded program be targeted or universal; and should the program cover children for one or two years of programming? Decisionmakers also wanted to know the cost of a high-quality program, how an expansion could leverage existing funding streams, and the possible return on investment. In answering these questions, stakeholders wanted to take a data-driven approach to preschool expansion, one that would be informed both by the broader research base but also by a deeper understanding of the current context of early learning programs in the city. The study demonstrates the way that research and analysis can inform the design of a preschool expansion at a state or local level by - integrating findings from studies of preschool program effects on short- and long-term outcomes for children - collecting and analyzing information on the local preschool landscape - conducting a financial analysis of the cost of alternative approaches to public-sector investments in preschool - analyzing the economic returns to those alternative investment strategies. These same building blocks can form the foundation for efforts by other communities seeking to take an evidence-based approach to early childhood investments. (author abstract)