<![CDATA[Mathematical abstraction ability is an essential higher-order thinking skill required for understanding abstract concepts in geometry. However, many junior high school students still experience difficulties in transitioning from concrete representations to abstract mathematical reasoning. This study aimed to develop an interactive learning medium to support students’ abstraction ability in learning plane geometry and examine its validity, practicality, and effectiveness. This research employed a Research and Development approach using the ADDIE model, which consists of analysis, design, development, implementation, and evaluation stages. The developed medium integrates interactive visualization, structured learning sequences, instructional videos, and practice activities designed to facilitate abstraction processes. The validation results showed that the medium achieved a validity percentage of 87.00%, categorized as very valid. The practicality test results indicated that the medium was very practical, with percentages of 87.50% in the limited trial and 87.70% in the field trial. Furthermore, effectiveness analysis using a pretest–posttest design revealed a medium normalized gain score (N-gain) of 0.56, indicating a meaningful improvement in students’ abstraction ability. These findings suggest that the interactive learning medium developed in this study is valid, practical, and effective for supporting abstraction ability in junior high school mathematics learning.]]>
Copyrights © 2026
