The difference in proportion of correct responses for each item between the top third of the class and the bottom third of the class is an example of a(n)
A)point biserial correlation.
B)discrimination index.
C)item difficulty.
D)guessing threshold.

Question

Quizplus · Accepted Answer

The discrimination index measures how well an item differentiates between high-performing and low-performing students, which is exactly what is described by comparing the proportion of correct responses between the top third and the bottom third of the class.

The Difference in Proportion of Correct Responses for Each Item