There are unique challenges to estimating causal effects of preschool for students with special needs that have not received attention in the literature. We revisit the Head Start Impact Study (HSIS) to illustrate that when and how special needs is defined has implications for the internal validity of and interpretation of special needs subgroup…

The objective of this study was to evaluate two early intervention packages to promote successful transitions to kindergarten for preschoolers with behavior problems recruited from Head Start preschools. Fifty children (M[subscript age] = 61 months; 76% male; 98% minority) referred by teachers due to early externalizing behavior problems were…

This paper uses data from the Head Start Impact Study (HSIS), a nationally representative multisite randomized trial, to quantify variation in effects of Head Start during 2002-2003 on children's cognitive and socio-emotional outcomes relative to the effects of other local alternatives, including parent care. We find that (1) treatment and control…

Care Quality Rating and Improvement Systems (QRISs) have advanced and matured, a number of states and localities have undertaken evaluations to validate the systems. Such efforts stem from the desire to ensure that the system is designed and operating in the ways envisioned when the system was established. Given that a central component in a QRIS…