Three basic questions concerning preschool education are discussed using information derived from research in early childhood education through 1963-1971. The questions are: (1) Does preschool education make a difference in later school performance of disadvantaged children? (2) If preschool education does make a difference, does it matter which curriculum theory is employed? and (3) How can educators guarantee effective preschool education? Findings indicate that (1) Preschool experience can make a difference for disadvantaged children. A few special situations have offered immediate positive impact in terms of their stated goals. Long-term data are not yet available. (2) From four types of curricula (Programmed, Open Framework, Child-Centered, and Custodial) two points can be made. First, children profit from any curriculum that is based on a wide range of experiences and second, the successful curriculum guides the teacher in adapting theory to the actual behaviors of children and (3) A successful program requires an effective staff model which in turn relies on planning and supervision. Educators should feel free to develop any curriculum that can be adapted to the needs of the children and the requirements of their staff model. (WY)