Evaluation of Examination Items for Assessing Students Using Rasch Model

Abstract

Examination item is an important instrument for measuring students’ achievement. The task to develop an instrument of high quality in assessing student’s ability is not easy. This study proposes a systematic procedure to measure the validity and reliability of instrument in assessing student’s ability. On top of that, it evaluates the ability of instrument in distinguishing between proficient and amateur students. Rasch measurement model was performed using Winstep Version 3.72.0.Datawere obtained from 18 items given by 44 Malaysian undergraduate students undertaking Statistics and Probability course for the 2010/2011 session. The reliability scores for the examination items and examined students were 0.95 and 0.82 each, after eliminating four misfit items and two misfit students. The reliability result exhibits high level of reliability in both examination items and examined students. The percentage of student’s ability and item difficulty were 88% and 71.4%, respectively which lies between -0.79 to 0.63logit. The capability of instrument to differentiate students with ability in this range is contributed by the presence of comparable items. The results provide important information concerning examination items reliability and validity, item difficulty and student’s ability. Finally, this study suggests improvement for future examination items.