In the post-pandemic world, open educational resources (OER) have the potential to ensure educational equity by providing all students with access to learning materials and by supporting teachers’ instructional practices through readily available, adaptable resources. However, the quality of OER continues to be a concern. Therefore, this study explored the use of (1) GeoGebra and scaffolding strategies to develop OER for secondary school mathematics teaching and (2) formative evaluation techniques to enhance the quality of the OER. A GeoGebra expert and a total of 40 frontline teachers participated in three review cycles of the OER development in the project. The feedback from each cycle informed the application of scaffolding strategies in the development of OER for the subsequent cycles. In Cycles 2 and 3, teachers rated the OER and provided feedback through surveys for further improvement. The results indicated that teacher ratings were significantly higher in Cycle 3 (n = 40, Mdn = 5) than in the previous cycle (n = 21, Mdn = 4) regarding the appropriateness of the OER for students with different learning preferences, z = − 2.87, p < 0.05. The results of the project-end satisfaction survey further revealed that all of the teacher participants were satisfied with the OER, which also enhanced their teaching practices. The results of the study offer a theoretical foundation that OER developers can ground upon to enhance their OER design. They also provide practical insights into the application of formative evaluation in the OER development that OER developers can adopt to create resources that are finely attuned to the needs of frontline teachers.

Keywords

open educational resources · scaffolding · formative evaluation · GeoGebra · mathematics education