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 study focuses on SEL implementation and includes results from surveys completed by educators and administrators who participated in an SEL implementation study during the 2019-2020 school year. The goal of the study was to better understand educators' and administrators' attitudes toward and beliefs about SEL prior to SEL implementation. This study utilized the Theory of Planned Behavior as an organizing framework through which to examine factors related to SEL implementation. Results show that while educators and administrators value SEL, they also perceive conditions within their schools that stand as barriers to implementation. Future research could continue to explore educators' and administrators' perspectives on SEL implementation under the Theory of Planned Behavior framework with larger, more heterogenous samples, and consider the impacts on implementation dosage and fidelity. [For the Executive Summary, see ED616534.]