医师资格考试单项选择题最优干扰选项数量分析

Research on Optimal Number of Multiple Choice Questions Distractors in Medical Licensing Examination

选择题存在无效干扰选项的情况,通过分析医师资格考试样本考生实测数据干扰选项的表现,按规则删除无效干扰选项后,分析了2～4个干扰选项对考试的影响。本研究发现:无效干扰选项占干扰选项总量的54.25%,每道试题平均有效干扰数量1.83个;有效干扰选项数量与难度值呈负相关,与区分度相关无统计学意义;随着干扰选项数量减少,考生总分均显著升高,整体组和中分组通过率单调升高;各方案难度和区分度均值的差异不显著,信度和效度均较好。研究结果表明,删减无效干扰选项不会对试题和试卷产生显著影响,医师资格考试最优干扰选项数量是3个。

Invalid distractors are commonly discovered in multiple choices questions. This study analyzes performance of distractors in Medical Licensing Examination in order to compare results between simulated tests with 2~4 distractors. Analysis shows that 54.25% of all distractors are invalid. The average number of invalid distractors for each question is 1.83. Item difficulty is significantly related with number of valid distractors, while item discrimination is not significantly related. Along with deletion of invalid distractors, monotonical increase is observed in total score for all groups of candidates, and in passing rate for all candidates as a whole and for middlelevel group of candidates. Difference of item difficulty and discrimination between groups is not significant. All groups show good reliability and validity. The study proves that deletion of invalid distractors shows no significant changes in item and test assessment. The optimal number of multiple choice questions distractors for Medical Licensing Examination is 3.