Effect of GeoGebra-Assisted Discovery Learning on Junior High School Students’ Conceptual Understanding of Straight-Line Equations

Abstract

Developing conceptual understanding remains a central challenge in mathematics education, particularly when students rely on procedural formulas without understanding the relationships among mathematical representations. This study examined whether GeoGebra-assisted discovery learning was associated with higher conceptual understanding of straight-line equations among eighth-grade students. A quasi-experimental posttest-only control-group design was employed involving 60 students from SMP Negeri 14 Tasikmalaya, Indonesia, assigned to an experimental class 30 students and a control class 30 students. The experimental group received GeoGebra-assisted discovery learning, whereas the control group received without GeoGebra-assisted discovery learning. Students’ conceptual understanding was assessed using a validated 5-item open-ended test. Data were analyzed using descriptive statistics and an independent-samples t-test, complemented by Cohen’s d to estimate the magnitude of the between-group difference. The experimental group obtained a higher mean posttest score (M = 11.10) than the control group (M = 8.47), and the difference was statistically significant (p = .003). The standardized mean difference was d = 0.79, indicating a substantial advantage for students who participated in GeoGebra-assisted discovery learning. Within the experimental group, 16.67% of students were classified as having high conceptual understanding, 70.00% moderate understanding, and 13.33% low understanding. These findings suggest that integrating dynamic GeoGebra representations into discovery-oriented activities can support students’ conceptual understanding of straight-line equations. The study provides empirical evidence for the instructional value of combining guided mathematical discovery with dynamic representations in junior high school mathematics