Analisis Kesalahan Siswa Dalam Pemahaman Konsep Matematika Pada Materi Bangun Datar Di Sekolah Dasar

An understanding of mathematical concepts relating to two-dimensional shapes is a crucial aspect of mathematics learning in primary school. However, there are still pupils who struggle to understand the properties of two-dimensional shapes, derive formulas, and solve problems accurately. This study aims to analyse the types and causes of pupils’ errors in understanding mathematical concepts relating to two-dimensional shapes, based on the stages of Newman’s Error Analysis (NEA). This study employed a descriptive qualitative approach and was conducted in Year 5 at SDN 3 Krasak Bangsri from January to March 2026. Research participants were selected using purposive sampling. Data were collected through a diagnostic test comprising 10 open-ended questions, semi-structured interviews, observation and documentation. Data analysis was carried out based on the five stages of NEA, namely reading, comprehension, transformation, process skills and encoding. Data validity was ensured through technique triangulation, source triangulation and member checking. The results of the study show that, out of 290 student responses, 193 contained errors and 97 were correct. The most prevalent type of error was the comprehension error, accounting for 74 responses (25.52 per cent), followed by transformation errors (67 responses, 23.10 per cent), process skills errors (32 responses, 11.03 per cent), encoding errors (14 responses, 4.83 per cent) and reading errors (6 responses, 2.07 per cent). The errors were caused by a lack of conceptual understanding, inaccuracies in determining strategies, difficulties with calculations, and a lack of precision in writing the final answers. This study demonstrates that NEA analysis can identify the sources of pupils’ errors step by step, providing a basis for improving mathematics learning. ABSTRAK Pemahaman konsep matematika pada materi bangun datar merupakan aspek penting dalam pembelajaran matematika di sekolah dasar. Namun, masih ditemukan siswa yang mengalami kesulitan dalam memahami sifat bangun datar, menentukan rumus, serta menyelesaikan soal secara tepat. Penelitian ini bertujuan untuk menganalisis jenis dan penyebab kesalahan siswa dalam memahami konsep matematika pada materi bangun datar berdasarkan tahapan Newman’s Error Analysis (NEA). Penelitian ini menggunakan pendekatan kualitatif deskriptif yang dilaksanakan di kelas V SDN 3 Krasak Bangsri pada Januari hingga Maret 2026. Subjek penelitian dipilih menggunakan teknik purposive sampling. Data dikumpulkan melalui tes diagnostik berupa 10 soal uraian, wawancara semi-terstruktur, observasi, dan dokumentasi. Analisis data dilakukan berdasarkan lima tahapan NEA, yaitu reading, comprehension, transformation, process skills, dan encoding. Keabsahan data melalui triangulasi teknik, triangulasi sumber, dan member check. Hasil penelitian menunjukkan bahwa dari 290 respons siswa, terdapat 193 respons yang mengalami kesalahan dan 97 respons benar. Kesalahan paling dominan terjadi pada tahap comprehension error sebanyak 74 respons (25,52%), diikuti transformation error sebanyak 67 respons (23,10%), process skills error sebanyak 32 respons (11,03%), encoding error sebanyak 14 respons (4,83%), dan reading error sebanyak 6 respons (2,07%). Kesalahan disebabkan oleh kurangnya pemahaman konsep, ketidaktepatan menentukan strategi, kesulitan perhitungan, serta kurangnya ketelitian dalam menuliskan jawaban akhir. Penelitian ini menunjukkan bahwa analisis NEA dapat mengidentifikasi letak kesalahan siswa secara bertahap sebagai dasar perbaikan pembelajaran matematika.