Online instruction, including online instruction that is blended with traditional in-person instruction, offers students more flexibility in the timing of their coursework and may deepen students' understanding of the material. By leveraging online courseware, colleges have the potential to expand college access, reduce costs, recruit a more diverse student population, and accelerate instruction under some conditions. Carnegie Mellon University's (CMU's) "Open Learning Initiative" ("OLI") provides online courses and learning materials to instructors and learners at low or no cost that can be presented in blended or purely online formats. "OLI" courses feature learning activities with immediate feedback for students and a dashboard for instructors to monitor student progress. This What Works Clearinghouse (WWC) report, part of the WWC's Supporting Postsecondary Success topic area, explores the effects of "OLI" on course completion rates and academic achievement. The WWC identified 12 studies of "OLI," three of which meet WWC standards. The evidence presented in this report includes studies of the impacts of "OLI" on community college students, including students who were White, Black, Hispanic, and Asian or Pacific Islander. [For "Open Learning Initiative (OLI). What Works Clearinghouse Intervention Snapshot," see ED602846. For "Open Learning Initiative (OLI). What Works Clearinghouse Intervention Brief," see ED602845.]