Quantitative Analysis of the Objective "X2 Type" Question in the New National Board Examination of Japan / 医学教育

The X2 type question consists of a multiple true-false method of testing, with 2 true and 3 false items. Its standard score rate is 56.6%, and its accidental score rate is 10%. Since the standard score rate of the present national board examination is almost 71%, the number of unsuccessful examinees will increase when the X2 type question is used while maintaining the same passing mark. Quantitative analysis shows that the score rate of X2 type questions is determined mostly by correct thinking on the most difficult true item and the most difficult false item. These results are important to the development of future examinations using X2 type questions.