International Journal of Physiology

One-best MCQs (Multiple Choice Questions) is a popular form of assessment where the student selects the best possible answer from the options provided. The objective of this study was to analyze the MCQs used in preliminary examinations in terms of Difficulty Index, Differentiation Index and Distracter efficiency.

Total 100 MCQ items with one correct option and three distracters were taken from past 5 years preuniversity examinations and analyzed for level of difficulty and power of discrimination. A total of 149, 156, 154, 156 and 148 students appeared for the exam in each year. The Difficulty index was calculated by the formula P = R/T. High and low groups consisting of upper and lower 27% students, respectively, were taken after arranging the scores in descending order for calculating the Discrimination Index as follows: DI = 2 x [(H-L)/N]. Distracter efficiency was determined on the basis of the number of Nonfunctioning Distracters (NF-Ds). An ideal item should have a DFI between 0.30–70.0, a DI of >0.24 and a DE of 100%.

The Difficulty indices for the ten papers of 10 MCQ`s each were (Mean±S. D) 0.50±0.24, 0.49±0.25, 0.52±0.23, 0.55±0.19, 0.73±0.22, 0.68±0.18, 0.53±0.24, 0.65±0.18, 0.54±0.3, 0.47±0.26 respectively. Differentiation indices were (Mean±S. D)0.37±0.12, 0.34±0.17, 0.35±0.14, 0.43±0.15, 0.40±0.15, 0.43±0.17, 0.40±0.20, 0.46±0.11, 0.40±0.16, 0.40±0.20. Thus as a whole, the papers were of average difficulty and were able to differentiate between the students. Thirtyfive MCQs were ideal MCQs. In individual analysis, total 37 MCQs were very easy (Difficulty Index>0.70) and 18 were found to be very tough (Difficulty Index<0.30). In Distracter analysis, 20% of the distracters were found to be nonfunctional (NFDs). 30% of the MCQ`s had One NFD, while 9% and 4% had two and three NFD`s respectively.

Overall, the papers had very good difficulty and differentiation indices which were quite consistent over the five years but there are a few MCQs and distracters which need to be modified to further enhance accurate assessment of the students.