ANALISIS PEMAHAMAN KONSEP MATEMATIKA SISWA KELAS VIII PADA MATERI TEOREMA PYTHAGORAS

This study aims to describe eighth-grade students’ understanding of mathematical concepts related to the Pythagorean Theorem based on their ability levels. The study employed a qualitative descriptive approach and was conducted at SMP Negeri 1 Kota Kupang during the even semester of the 2025/2026 academic year. The research subjects consisted of three students representing high, moderate, and low ability levels, who were selected through purposive sampling based on information from the mathematics teacher. Data were collected through Conceptual Understanding Tests (CUT) I and II as well as semi-structured interviews. Data analysis was conducted through data reduction, data presentation, and drawing conclusions. Data validity was tested using temporal triangulation by comparing CPT results at different times and confirming them through interviews. The results showed that high-ability subjects were able to meet the four indicators of conceptual understanding: restating concepts, representing concepts, identifying elements of concepts, and applying concepts. Students with moderate ability were also able to meet all four indicators, but their explanations remained simple, and some written answers showed inaccuracies. Students with low ability were not yet able to optimally meet all four indicators and experienced difficulties in understanding, representing, identifying, and applying the Pythagorean Theorem. The findings indicate differences in conceptual understanding based on students’ ability levels and highlight the importance of learning. ABSTRAK Penelitian ini bertujuan untuk mendeskripsikan pemahaman konsep matematis siswa kelas VIII pada materi Teorema Pythagoras berdasarkan tingkat kemampuan siswa. Penelitian menggunakan pendekatan deskriptif kualitatif dan dilaksanakan di SMP Negeri 1 Kota Kupang pada semester genap tahun ajaran 2025/2026. Subjek penelitian terdiri atas tiga siswa yang mewakili kemampuan tinggi, sedang, dan rendah, yang dipilih secara purposive berdasarkan informasi dari guru matematika. Data dikumpulkan melalui Tes Pemahaman Konsep (TPK) I dan II serta wawancara semi-terstruktur. Analisis data dilakukan melalui reduksi data, penyajian data, dan penarikan kesimpulan. Keabsahan data diuji menggunakan triangulasi waktu dengan membandingkan hasil TPK pada waktu yang berbeda dan mengonfirmasinya melalui wawancara. Hasil penelitian menunjukkan bahwa subjek berkemampuan tinggi mampu memenuhi empat indikator pemahaman konsep, yaitu menyatakan ulang konsep, merepresentasikan konsep, mengidentifikasi unsur konsep, dan menerapkan konsep. Subjek berkemampuan sedang juga mampu memenuhi keempat indikator, tetapi penjelasan masih sederhana dan terdapat ketidaktelitian pada beberapa jawaban tertulis. Subjek berkemampuan rendah belum mampu memenuhi keempat indikator secara optimal dan mengalami kesulitan dalam memahami, merepresentasikan, mengidentifikasi, serta menerapkan konsep Teorema Pythagoras. Temuan menunjukkan adanya perbedaan pemahaman konsep berdasarkan tingkat kemampuan siswa dan pentingnya pembelajaran yang menekankan pemaknaan konsep, representasi, ketelitian, dan penerapan dalam konteks masalah.