OER Knowledge CloudJournal ArticleAnghel, EllaLittenberg-Tobias, JoshuaVon Davier, MatthiasThe growing interest in professional development for teachers via massive open online courses (MOOCs) raises the need for identifying the existing gaps in the literature on the topic. In this literature review, we were able to identify 68 relevant studies. They mostly used mixed methods (57%) and surveys (82%), and only reported descriptive statistics (52%). They also tended to measure participants’ attitudes (41%) and engagement (40%). Based on our findings, we recommend that future researchers consider additional data collection and analysis methods (e.g., clickstream data, objective performance measures) and use correlational, longitudinal, and experimental designs.20252025/05/08EnglishThe International Review of Research in Open and Distributed Learning262130-161United States10.19173/irrodl.v26i2.8311https://www.irrodl.org/index.php/irrodl/article/view/83111492-3831yesmassive open online coursesscoping reviewteacher professional developmentin-service teachershttps://www.irrodl.org/index.php/irrodl/article/view/83118311_Anghel.pdfUnited States, North America