<![CDATA[This study was motivated by the goal of developing a test instrument aligned with the indicators of fifth-grade elementary school students’ mathematical concept comprehension in the topic of fractions. The research was conducted using the Research and Development method, following the Analysis, Design, Development, Implementation, and Evaluation (ADDIE) stages. The study was carried out at an elementary school in Karawang. The research subjects were 24 fifth-grade elementary school students selected through purposive sampling. The testing instrument was an essay test consisting of 16 questions containing several indicators of mathematical concept understanding, including: 1) Independently restating concepts; 2) Grouping objects based on specific characteristics; 3) Distinguishing examples and non-examples of a concept; 4) Presenting concepts in various forms of representation (tables, graphs, symbols, etc.); 5) Determining necessary and sufficient conditions that define a concept; 6) Applying mathematical procedures accurately; 7) Solving problems using appropriate concepts. The development of the instrument began with an expert judgment validation process, followed by empirical testing to determine the levels of validity, reliability, difficulty index, and discriminative power. The results show that 13 out of 16 items were deemed valid with an instrument reliability of 0.95, indicating a very high level of consistency. In addition, an evaluation of the item characteristics revealed that the difficulty level ranged from easy to moderate, with discriminative power ranging from good to very good. These findings indicate that the 13 items developed meet the quality standards for an assessment instrument suitable for measuring fifth-grade elementary school students’ understanding of mathematical concepts, particularly regarding fraction operations.]]>
