Although extensive research exists on vocabulary instruction during book reading in preschool classroom, comparatively little research has been conducted on vocabulary exposure in classroom play contexts and child vocabulary outcomes. The purpose of this study was to examine Head Start teacher and child vocabulary use in dyadic play sessions and…

Studies of small-scale "model" early-childhood programs show that high-quality preschool can have transformative effects on human capital and economic outcomes. Evidence on the Head Start program is more mixed. Inputs and practices vary widely across Head Start centers, however, and little is known about variation in effectiveness within…