Abstract
Although preschool for disadvantaged children is strongly supported nationally as a beneficial endeavor, the research that underlies this support has mostly been limited to small-scale, high-quality programs. Some have questioned the ability of public schools to provide similar experiences and outcomes for young children. This study finds that large-scale public school programs can provide developmentally appropriate experiences for disadvantaged young children that contribute to increased skills in first grade. Based on a measure of fidelity of implementation of the High/Scope curriculum, it appears that programs implementing the curriculum moderately to very well contribute more to school success than programs with low levels of implementation. It is recommended that policy makers consider the use of a system combining ongoing evaluation of practices with staff training as a way of maintaining high levels of program implementation and effectiveness.