Growing investments in preschool at the federal and state levels--particularly in evidence-based approaches to language acquisition and reading--are predicated in part on the hope that high-quality preschools might help close the gap between the school achievement of low-income children and their more affluent peers. Indeed, the problem is…

Professional development--formal in-service training to upgrade the content knowledge and pedagogical skills of teachers--is widely viewed as an important means of improving teaching and learning. While many interventions "include" professional development, professional development was the central intervention of the two recent research and…