Abstract
This study aims to develop and analyze the quality of a formative test instrument on fraction material for fifth-grade elementary school students using the Research and Development (R&D) method. The development process comprised the stages of needs analysis, blueprint construction, item writing, expert validation, field testing, and item analysis using the Classical Test Theory (CTT) approach. Data were collected through a tryout involving 30 students using 20 multiple-choice items. The analysis was conducted to determine item difficulty, discrimination index, distractor function, item validity, and instrument reliability. The results indicate that all items were declared valid, with difficulty levels ranging from easy to moderate. The reliability coefficient of r11 = 0.934 indicates that the instrument possesses very high internal consistency. This instrument can be used as a formative assessment tool to measure students' understanding of fraction concepts, encompassing addition, subtraction, multiplication, division, and comparison of fractions. This study further underscores the importance of construct validity and effective distractor functioning in producing high-quality assessment instruments.