<![CDATA[This study aims to analyze in-depth the types of student errors and their causal factors in solving relation and function problems using the discovery learning model. This study was conducted in 2025 using a qualitative descriptive approach. The subjects were eighth-grade students of SMP PGRI 8 Malang, with four students selected purposively based on error variations. The research instruments were essay tests and unstructured interviews. The results showed that student errors included conceptual errors, principle errors, and operational errors. Conceptual errors were the dominant errors caused by a weak understanding of relation and function representations. Principle errors occurred due to inaccuracies in using solution procedures, while operational errors were related to the accuracy of symbol use and calculations. These findings indicate that even though discovery learning has been implemented, students still experience difficulties without adequate scaffolding. ABSTRAK Penelitian ini bertujuan untuk menganalisis secara mendalam jenis kesalahan siswa dan faktor penyebabnya dalam menyelesaikan soal relasi dan fungsi melalui model discovery learning. Penelitian ini dilaksanakan pada tahun 2025 dengan pendekatan deskriptif kualitatif. Subjek penelitian adalah siswa kelas VIII SMP PGRI 8 Malang, dengan empat siswa dipilih secara purposif berdasarkan variasi kesalahan. Instrumen penelitian berupa tes uraian dan wawancara tidak terstruktur. Hasil penelitian menunjukkan bahwa kesalahan siswa meliputi kesalahan konsep, kesalahan prinsip, dan kesalahan operasi. Kesalahan konsep merupakan kesalahan dominan yang disebabkan oleh lemahnya pemahaman terhadap representasi relasi dan fungsi. Kesalahan prinsip terjadi akibat ketidaktepatan dalam menggunakan prosedur penyelesaian, sedangkan kesalahan operasi berkaitan dengan ketelitian dalam penggunaan simbol dan perhitungan. Temuan ini mengindikasikan bahwa meskipun discovery learning telah diterapkan, siswa masih mengalami kesulitan jika tidak didukung oleh scaffolding yang memadai. ]]>
