The Levels Of Difficulty And Discrimination Indices In Type A Multiple Choice Questions Of Pre-clinical Semester 1 Multidisciplinary Summative Tests

Item analysis is the process of collecting, summarizing and using information from students' responses to assess the quality of test items. Difficulty index (P) and Discrimination index (D) are two parameters which help evaluate the standard of MCQ questions used in an examination, with abnormal values indicating poor quality. In this study, 120 test items of 12 Type A MCQ tests of Foundation 1 multi-disciplinary summative assessment from M2 / 2003 to M2 / 2006 cohorts of International Medical University were selected and their P-scores in percent and D-scores were estimated using Microsoft Office Excel. The relationship between the item difficulty index and discrimination index for each test item was determined by Pearson correlation analysis using SPSS 11.5. Mean difficulty index scores of the individual summative tests were in the range of 64% to 89%. One-third of total test items crossed the difficulty index of 80% indicating that those items were easy for the students. Sixty seven percent of the test items showed acceptable (> 0.2) discrimination index. Forty five out of 120 test items showed excellent discrimination index. Discrimination index correlated poorly with difficulty index (r = -0.325). In conclusion, a consistent level of test difficulty and discrimination indices was maintained from 2003 to 2006 in all the twelve summative type A MCQ tests.