If an item-discrimination index is negative
A) high scorers are more likely to have answered the item correctly than low scorers.
B) low scorers are more likely to have answered the item correctly than high scorers.
C) the alternate form of the test is probably not equivalent.
D) the computer scoring is in error because this index is not supposed to be negative.

Question

Quizplus · Accepted Answer

A negative item-discrimination index indicates that low scorers are more likely to answer the item correctly than high scorers, suggesting that the item may not be measuring what it's intended to measure. Option A is incorrect because a positive discrimination index indicates that high scorers are more likely to answer the item correctly. Option C is also incorrect because the issue is with the item itself, not with the equivalence of alternate forms. Option D is incorrect because negative discrimination indices are possible and are not an error in computer scoring.

If an Item-Discrimination Index Is Negative