The item-discrimination index can vary from
A) 0 to 100
B) -1.0 to +1.0
C) 0.0 to +1.0
D) 0.5 to +1.0

Question

Quizplus · Accepted Answer

The item-discrimination index measures how well an item distinguishes between high-performing and low-performing examinees. It can range from -1.0 (all low-performing examinees answer correctly and all high-performing examinees answer incorrectly) to +1.0 (all high-performing examinees answer correctly and all low-performing examinees answer incorrectly), with 0 indicating no discrimination.

The Item-Discrimination Index Can Vary from