Starting in the 2019-2020 school year, NewSchools Venture Fund awarded a research grant to ACT to better understand factors related to social and emotional learning (SEL). SEL lessons were implemented in schools serving students who were 96% Latinx, 85% economically disadvantaged, and 38% English learners during the 2019-2020 school year. The overarching goal of the research was to determine the efficacy of SEL lessons while also examining factors affecting SEL implementation. To understand the factors related to successful implementation, ACT sought perspectives from multiple stakeholders, including students, educators, administrators, and families. Findings are reported in a series of issue briefs, and each brief highlights findings gleaned from various stakeholders involved. This executive summary provides a broad overview of each component of the research, underscores key findings from each brief, and provides implications for research and practice.