Trends and Gaps in Empirical Research on Open Educational Resources (OER): A Systematic Mapping of the Literature from 2015 to 2019

For almost 20 years, Open Educational Resources (OER) are an integral part of the debate about the digitisation of education. However, the empirical landscape of OER research is vivid and largely obscure.
This article reviews the state of international empirical research on OER to reveal trends and gaps and, in this manner, identify possible desiderata for further research. We use a systematic mapping approach to examine the empirical English-speaking research landscape from 2015 to 2019. The results reveal that research primarily concentrates on the higher education sector, while only a few studies are available for the school and other educational sectors. In terms of research methodologies, quantitative approaches
are prevalent, with most of them being survey-based. The main research interests of the empirical studies lie in the perception of OER and the barriers to their use in educational practices. Open textbooks as a form of OER and their comparative cost advantages or qualitative comparability with traditional
educational material constitute an emerging research field that is almost exclusively located in the U.S.
Research gaps exist regarding the usability and user-friendliness of OER repositories. Addressing these gaps could support the numerous initiatives in different countries to establish and equip repositories.
Additional gaps for empirical research were identified regarding the effects of the use of OER on pedagogical approaches and established educational practices.