From Classroom to Long‑Term Results: The Impact of Inquiry‑Based Teaching on Student Achievement and Retention in Geometry

This study explores the impact of inquiry-based learning on the students’ performance and retention of geometric knowledge. The study adopted a descriptive case study and design-based approach as the research design and approach, respectively. The three stages of a design-based framework were used: design, implementation and evaluation, and documentation and reflection. Eight in-service mathematics teachers and eighty-seven students were sampled from two senior high schools. The study was conducted in two phases. Professional development programmes were organised to train teachers in designing and implementing inquiry-based geometry lessons grounded in constructivist pedagogy. The intervention was refined and went through four iterative cycles and was tested in actual classroom settings. Data were collected using geometry achievement tests and focus group discussions. Sample geometry achievement test and focus group protocols were developed and reviewed by experts. Data from the tests were analysed using a paired t-test and one-way analysis of variance (ANOVA), while focus group discussions data were analysed using thematic analysis. The study’s findings revealed an improvement in the senior high school students' performance and long-term knowledge retention in geometry. The results suggest an association between inquiry-based learning and improved performance/retention, while acknowledging that causality cannot be confirmed without a control group. From the focus group discussion data, collaboration, mode of delivery, and interest were the themes that the students admitted contributed to their ability to retain the geometry knowledge they had constructed. The study recommended that mathematics teachers who are enthusiastic about enhancing their pedagogical approaches and improving students’ learning outcomes should consider inquiry-based approaches.

Keywords Inquiry-based approach · Descriptive case study · Design-based
approach · Performance · Retention · Knowledge and geometry