Item Analysis of EFL Test Using AnBuSo: Difficulty, Discrimination Power, and Distractor Functionality

Abstract

This study investigates the quality of a teacher-constructed English language multiple-choice test using item analysis through AnBuSo (Analisis Butir Soal). The test, which consisted of 30 items assessing vocabulary, grammar, and reading comprehension, was administered to 20 students from the WINA Choir Program at STKIP Widya Yuwana, Madiun. Utilizing a quantitative descriptive design, the research focused on evaluating item difficulty, discrimination power, and distractor functionality. Results showed that 83% of the items had moderate difficulty, while 73% demonstrated good discrimination indices. However, several items were found to have non-functional distractors or negative discrimination values, indicating the need for revision. The findings underscore the importance of item analysis in improving test quality and enhancing its diagnostic value. The study highlights how digital tools like AnBuSo can support effective assessment practices and guide teachers in revising items and designing targeted remedial instruction.