Analysis of Students’ Error Patterns in Trigonometry Diagnostic Tests Using the GetMath Platform in Senior High Schools in Banda Aceh

Abstract

Understanding trigonometric concepts remains a major challenge for senior high school students, as indicated by the high prevalence of conceptual and procedural errors in solving trigonometry problems. These difficulties are often not adequately identified through conventional assessments, highlighting the need for diagnostic assessments capable of revealing students’ error patterns in greater depth. This study aims to analyze the characteristics of trigonometry diagnostic test items and students’ answer error patterns in senior high schools in Banda Aceh using the GetMath platform. This study employed a descriptive quantitative approach. The research subjects consisted of 200 students from three public senior high schools in Banda Aceh, namely SMAN 3, SMAN 5, and SMAN 10 Fajar Harapan, selected through purposive sampling. The research instrument was a trigonometry diagnostic test comprising 13 multiple-choice items with option levels (D0–D4), developed based on the Cognitive Diagnostic Assessment (CDA) framework. Data were collected digitally through the GetMath platform and analyzed descriptively to examine the distribution of students’ answer errors at each option level. The results indicate that students’ error patterns varied across schools. The highest percentage of correct answers was achieved by students from SMAN 5 Banda Aceh (49%), followed by SMAN 10 Fajar Harapan (41%) and SMAN 3 Banda Aceh (27%). The most dominant errors were classified as most severe errors and minor errors, indicating low levels of students’ conceptual and procedural understanding of trigonometric material. These findings suggest that a substantial proportion of students continue to experience difficulties in comprehending and applying trigonometric concepts. Therefore, the implementation of diagnostic tests should be followed by targeted remedial and enrichment programs, adequate supervision during test administration, enhanced student motivation and participation, and optimal scheduling and testing conditions to ensure that assessment results more accurately reflect students’ actual abilities.