PENINGKATAN KEMAMPUAN BERPIKIR GEOMETRI SISWA SMA PADA FUNGSI TRIGONOMETRI MELALUI MODEL CRA BERBANTUAN DESMOS - Zahratul Didiniyah; Fiki Alghadari; Nurul Hidayah (Pusat Pengembangan Pendidikan dan Penelitian Indonesia (P4I), 2026)
This study was motivated by the low level of students’ geometric thinking skills in trigonometric function material. Students still face difficulties in understanding geometric concepts visually and abstractly because learning tends to focus on memorizing formulas. This study aimed to determine the difference in the improvement of geometric thinking skills between students taught using the Concrete-Representational-Abstract (CRA) model assisted by Desmos and those taught through conventional learning. The research employed a quasi-experimental method with a pretest-posttest control group design. The sample consisted of 64 eleventh-grade students of SMA Negeri 1 Tebo divided into an experimental class and a control class. The research instrument was a geometric thinking skills test based on Van Hiele theory. Data were analyzed using normality tests, N-Gain analysis, and the Mann-Whitney test. The results showed that the average N-Gain score of the experimental class was 0.6102, higher than the control class score of 0.2068. The Mann-Whitney test produced a significance value of 0.000 < 0.05, indicating a significant difference between the two groups. Therefore, the CRA model assisted by Desmos was more effective than conventional learning in improving students’ geometric thinking skills. ABSTRAK Penelitian ini dilatarbelakangi oleh rendahnya kemampuan berpikir geometri siswa pada materi fungsi trigonometri. Siswa masih mengalami kesulitan memahami konsep geometri secara visual dan abstrak karena pembelajaran lebih berfokus pada hafalan rumus. Penelitian ini bertujuan untuk mengetahui perbedaan peningkatan kemampuan berpikir geometri antara siswa yang belajar menggunakan model Concrete-Representational-Abstract (CRA) berbantuan Desmos dan siswa yang belajar melalui pembelajaran konvensional. Penelitian menggunakan metode quasi experiment dengan desain pretest-posttest control group design. Sampel penelitian terdiri dari 64 siswa kelas XI SMA Negeri 1 Tebo yang dibagi menjadi kelas eksperimen dan kelas kontrol. Instrumen penelitian berupa tes kemampuan berpikir geometri berdasarkan teori Van Hiele. Data dianalisis menggunakan uji normalitas, N-Gain, dan uji Mann-Whitney. Hasil penelitian menunjukkan bahwa rata-rata N-Gain kelas eksperimen sebesar 0,6102 lebih tinggi dibandingkan kelas kontrol sebesar 0,2068. Uji Mann-Whitney memperoleh nilai signifikansi 0,000 < 0,05 yang menunjukkan adanya perbedaan peningkatan kemampuan berpikir geometri antara kedua kelas. Dengan demikian, model CRA berbantuan Desmos lebih efektif dibandingkan pembelajaran konvensional.