This issue brief is part of a five-part series that reports findings from research conducted by ACT in collaboration with Region One Education Service Center. This brief focuses on the efficacy of social and emotional learning (SEL) lessons implemented and includes results from surveys completed by students who participated in an SEL lessons during the 2019-2020 school year. The goal of the study was to better understand students' reactions to SEL lessons, including whether they found the lessons engaging, whether they acquired knowledge and skills, and whether they were able to apply content from the lessons in and out of school. Results from the study suggest SEL programming may be an effective way to support learners who have been historically underserved and who often need additional supports because they face significant barriers to college entry and completion. This research can help inform efforts to focus on the whole child in education while supporting diverse learners. [For Brief 1 in the series, see ED616537. For the Executive Summary, see ED616534.]