Assessing an assessment tool: Analysis of multiple choice questions on difficulty level and discrimination power, from an assessment in physiology

ABSTRACT

Background: Multiple Choice Questions (MCQs) or ‘‘items” are frequently used in medical education to assess students’ knowledge at the end of an academic session. However, item analysis has to be done to confirm their excellence. This piece of work was aimed to analyze test items in the subject of Physiology. In view of the fact that item analysis has never been conducted in our physiology department, thus this study was planned to assess the quality of MCQs and construct a viable question bank. Aim and Objectives: To evaluate the quality of MCQs used so as to develop a pool of valid items to update the question bank. Materials and Methods: Total of one hundred 1st year MBBS students were given 40 MCQs. Analysis was done with the item difficulty and item discrimination indices. Results: Difficulty indices (p) of 14 items were easy while about two MCQ were difficult and the remaining 24 of the items were within acceptable range. The discrimination index (DI) (D) for 40 items; one item showed negative discrimination, ten were having poor discrimination, whereas 11 were having excellent discrimination.Nine items were having acceptable, and nine items were having good discrimination. The DI exhibited slight positive correlation with difficulty index (r = 0.1575 P = 0.05). However, it was not statistically significant. Conclusion: The findings show that most of the items were falling in acceptable range of difficulty and discrimination level. It concludes that Item analysis is a very useful and necessary procedure to obtain valid Items from time to time.