EDC researchers performed secondary analysis of quantitative and qualitative data to better understand the nature of collaboration and the relationship between different types of collaboration and desired outcomes for programs, teachers, classrooms, and children. The objectives of our research were to answer three distinct questions: 1. What types of early care and education programs are engaged in collaboration, and what is the nature of collaboration among child care, Head Start, and preK providers? 2. What factors at the federal, state, and local levels either promote or hamper efforts among programs to collaborate? 3. What is the relationship between different types of collaboration and desired outcomes for programs, teachers, classrooms, and children? We focused our inquiry on the years 2003-2009 but included historical information that helped to describe the nature of collaborations in existence. (author abstract)