This evaluation study was conducted by the Connecticut Academy of Science and Engineering (CASE) on behalf of the Connecticut General Assembly (CGA) at the request of the Education Committee. The purpose of this study is to investigate the immediate effects associated with children who attend Connecticut's state-funded School Readiness full-day or school-day prekindergarten program. The primary research questions include: 1. Do children who attend full-day or school-day, state-funded preschool programs enter kindergarten with better language and literacy skills than if they had not attended the program? 2. Do children who attend full-day or school-day, state-funded preschool programs enter kindergarten with better mathematics skills than if they had not attended the program? 3. Do children who attend full-day or school-day, state-funded preschool programs enter kindergarten with better social skills than if they had not attended the program? (author abstract)