Item analysis A tool to increase MCQ validity
Background: Multiple Choice Questions (MCQs) are a popular assessment tool due to their high objectivity, high reliability and the ability to assess a large content in a short time span. However their validity cannot be taken for granted and needs to be ascertained by various means. Item analysis is one such process of testing MCQ validity by assigning certain numeric indices to them and comparing these with acceptable standards. Aims and objectives: The aim of the present study was to demonstrate the use of item analysis as a tool to ascertain MCQ validity. Material and methods: Sixty MCQs in ophthalmology of the single best response type were subjected to the process of item analysis and the difficulty index, discrimination index and distracter effectiveness were calculated using standard formulae. These MCQs and distracters were then classified into groups as per standard reference ranges of these parameters and the absolute number and percentage of MCQs and distracters in each group were calculated. Results: The percentage of MCQs that could be accepted as having desired validity based on difficulty index, discrimination index and distracter effectiveness were 50% 33% and 32% respectively while 63% of the distracters were functional (acceptable) Thus these MCQs could be used for assessment while the rest needed modification and retesting or needed to be discarded. Conclusion: MCQ item analysis must be performed to filter MCQs of acceptable validity which would increase their quality as assessment tools thereby making assessment more meaningful.