Quantitative analysis of single best answer multiple choice questions in pharmaceutics

The purpose of this study was to: (1) analyze the quality of single best answer multiple choice questions (MCQs) used in pharmaceutics exams, (2) identify the correlation between difficulty index (DIF I), discriminating index (DI), and distractor efficiency (DE), and (3) understand the relationship between DIF I, DI, and DE and the number of MCQ answer options and their cognitive level.

429 MCQs used in pharmaceutics exams were analyzed. The quality of the MCQs was evaluated using DIF I, DI, and DE. The number of answer options and the cognitive level tested by each item were evaluated. Relationships between DIF I, DI, and DE were measured using Pearson's correlations and t-tests.

DIF I showed a significant negative correlation with DI within questions that measured information recall. A significant negative correlation between DIF I and DI was observed in questions with four and five answer options regardless of the cognitive level measured. The highest DI values were found in moderate difficulty questions, while the worst DE was observed for the easiest questions. Questions that measured analytical and problem-solving abilities were more difficult than those measuring information recall. Questions with four and five answer options had excellent discrimination.

Single best answer MCQs are a valuable assessment tool capable of evaluating higher cognitive skills. Significant correlation between DIF I and DI can indicate the examination quality. Higher quality MCQs are constructed using four and five answer options.