The relationship between non-functioning distractors and item difficulty of multiple choice questions: A descriptive analysis

Objectives: This study investigates the relationship between the presence of non-functioning distractors (NFDs) and the difficulty index of multiple choice questions (MCQs). Materials and Methods: The number of NFDs and difficulty index were correlated for each MCQ of Family Medicine Examination, College of Medicine, King Saud University (KSU) in three consecutive years (2010, 2011 and 2012). Results: The MCQs with more NFDs showed high difficulty index as compared to MCQs having less NFDs. The pattern of increasing difficulty index was 1NFD < 2NFD < 3NFD. However, the MCQs with a lesser number of NFDs would not necessarily be always difficult. Conclusion: MCQs with a higher number of NFDs are easier than those with lower number of NFDs