OER Knowledge CloudJournal ArticleTlili, AhmedZhang, XianglingLampropoulos, GeorgiosSalha, SoheilGarzón, JuanBozkurt, ArasHuang, RonghuaiBurgos, DanielConflicting results exist in the literature on whether Open Educational Resources (OER) and Open Educational Practices (OEP) can improve learning performance. Additionally, limited studies, in this context, have attempted to systematically measure and understand this phenomenon. To address this research gap, this study conducts a two-level analysis based on a systematic review of the OER and OEP literature. It first conducts a meta-analysis to measure the effect of OER and OEP on learning performance. It then conducts a meta-synthesis based on the activity theory to understand what led to this effect (measured in the first phase). Specifically, 32 studies (N = 134905 participants) were quantitatively and qualitatively analyzed. The obtained results revealed that OER and OEP have significant negligible effect (g = 0.10; p < 0.05), which indicates that learners are mostly consumers of knowledge in a very traditional way. Additionally, it is found that the learning process was mainly in formal settings in classrooms using traditional technologies like websites and learning management systems. The findings of this study can help to enhance the effective adoption of OER and OEP by highlighting the confounding variables that should be considered when developing their open education initiatives.20252025/04/10EnglishSpringer NatureHumanities and Social Sciences Communications125041-13ChinaChinaChinaChinaChinaChinaChinaChina10.1057/s41599-025-04644-yyesopen educational resourcesOERopen educational practicesOEPlearning performanceadoptions41599-025-04644-y.pdfChina, Greece, Cyprus, Palestinian Territories, Colombia, Turkey, Spain, United States