Project Summary/Abstract Children from economically disadvantaged families are at risk for starting school behind their more affluent peers.1,2 Pre-academic skills and the development of executive functions (EF), our focus in the proposed study, are two key aspects of school readiness that contribute to long-term trajectories of social and academic success.3,4 In this secondary data analysis study, we focus on the quality of teacher-child interactions in the classroom as a key lever to improve early school functioning. Specifically, the quality of both individual teacher-child interactions and classroom-level teacher instructional and emotional support have been linked to development of school readiness skills,5-7 but the ways in which these two aspects of teacher interactional quality interact to promote children’s early learning is unclear. The overall goal of this project is to both identify and disentangle the effects of individual teacher-child relationship quality and classroom-level support on children’s development of pre-academic and EF skills across one year of Head Start. Using a child-centered analysis, we will identify multidimensional constellations, or profiles, of individual and classroom-level teacher interactional quality, for whom these profiles exist (by examining child and teacher characteristics), how these profiles change across the school year, and how membership in these profiles is linked to growth in school readiness skills. Identifying patterns of teacher interactional quality that facilitate children’s early learning will contribute to enhancing Head Start practice and developing interventions to close school readiness achievement gaps, ultimately facilitating long-term school success for children from economically disadvantaged backgrounds. We will use data from the Head Start CARES (Classroom-based Approaches and Resources for Emotion and Social skill promotion) dataset, which includes 307 teachers and 2,114 four-year-old children representing the national Head Start population, and features rich data on teachers, classrooms, and longitudinal school readiness outcomes. We will use complementary person-centered and multi-level variable-centered and analytical approaches to achieve the study goals. Our novel approach to considering classroom interactional quality will inform the future development of classroom interaction interventions matched to the needs of individual teachers and children to promote the acquisition of pre-academic and EF skills among Head Start participants and other economically disadvantaged children.