This report’s findings shed light on the everyday contributions Head Start assistant teachers make to classroom quality, measured through teacher-child interactions. This report aims to help policymakers, education administrators, and practitioners understand the importance of assistant teachers to the quality of Head Start programming, and particularly their role in supporting the growing population of dual language learning (DLL) children in Head Start. The findings could have implications for policy development that positively supports practices that train, develop, and retain assistant teachers in the workforce pipelines of Head Start and other ECE settings. (author abstract)