Item analysis of in use multiple choice questions in pharmacology.

BACKGROUND

Multiple choice questions (MCQs) are a common method of assessment of medical students. The quality of MCQs is determined by three parameters such as difficulty index (DIF I), discrimination index (DI), and distracter efficiency (DE).

OBJECTIVES

The objective of this study is to assess the quality of MCQs currently in use in pharmacology and discard the MCQs which are not found useful.

MATERIALS AND METHODS

A class test of central nervous system unit was conducted in the Department of Pharmacology. This test comprised 50 MCQs/items and 150 distracters. A correct response to an item was awarded one mark with no negative marking for incorrect response. Each item was analyzed for three parameters such as DIF I, DI, and DE.

RESULTS

DIF of 38 (76%) items was in the acceptable range (P = 30-70%), 11 (22%) items were too easy (P > 70%), and 1 (2%) item was too difficult (P < 30%). DI of 31 (62%) items was excellent (d > 0.35), of 12 (24%) items was good (d = 0.20-0.34), and of 7 (14%) items was poor (d < 0.20). A total of 50 items had 150 distracters. Among these, 27 (18%) were nonfunctional distracters (NFDs) and 123 (82%) were functional distracters. Items with one NFD were 11 and with two NFDs were 8. Based on these parameters, 6 items were discarded, 17 were revised, and 27 were kept for subsequent use.

CONCLUSION

Item analysis is a valuable tool as it helps us to retain the valuable MCQs and discard the items which are not useful. It also helps in increasing our skills in test construction and identifies the specific areas of course content which need greater emphasis or clarity.