New York University will create a center to conduct secondary analysis of data from the Head Start Impact Study (HSIS). These analyses will extend HSIS findings to address how features of Head Start centers are associated with variation in program impacts on key child outcomes of cognitive functioning, social-emotional skills, and health status. The proposed study will inform Head Start in three ways: how workforce characteristics and organizational structures of centers and grantees might explain variation in center-level impacts of Head Start, the impact of investment and implementation in different features of Head Start, and finally, program features particularly relevant to dual-language learners and children from immigrant families.