Journal of Research in Medical Education & Ethics
  • Year: 2015
  • Volume: 5
  • Issue: 3

Item Analysis of MCQs and Correlation between Difficulty Index, Discrimination Index and Distractor Efficiency in a Formative Examination in Community Medicine

1Assistant Professor, Department of Community Medicine, MVP's Dr. Vasantrao Pawar Medical College, Hospital and Research Centre, Nashik, Maharashtra, India

2Associate Professor, Department of Community Medicine, MVP's Dr. Vasantrao Pawar Medical College, Hospital and Research Centre, Nashik, Maharashtra, India

*Corresponding author email id: drsupriyadhakne@gmail.com

Online published on 10 December, 2015.

Abstract

Item analysis is an important tool to assess the validity of Multiple Choice Questions (MCQs), in terms of difficulty index, discrimination index and distractor efficiency.

Present study aims at testing the validity of MCQs of a formative examination in Community Medicine using these parameters and to study the correlation between the parameters.

This item analysis was carried out for 30 single-best-response MCQs with 90 distractors. Responses of total of 96 students were analysed.

The mean difficulty index was found to be 61.09±16.98. The mean discrimination index was found to be 0.36±0.18. Negative correlation was found between DIF-I and DIS-I (r=0.1645, p<0.01). The overall distractor efficiency was found to be 77.78%. The mean number of distractors and DIF-I of the MCQ item showed a negative correlation (r=-0.5778, p<0.01). The mean number of distractors and DIS-I of the MCQ item showed a positive correlation (r=0.2231, p<0.01).

Having DIF-I and DIS-I as well as distractor analysis of each MCQ item at hand, the same MCQ item can be used in subsequent examinations with necessary changes. With such constant modification, eventually very well constructed MCQ items can be generated.

Keywords

Item analysis, Difficulty index, Discrimination index, Distractor efficiency, Psychometric analysis