Which of the following test items is best (a, b, c, or d), where p is the item difficulty index and D the item discrimination index?
A) p = .30, D = .50
B) p = .50, D = .50
C) p = .70, D = .20
D) p = 1.00, D = .50

Question

Quizplus · Accepted Answer

An ideal test item has a difficulty index (p) around .50, meaning it is neither too hard nor too easy, and a high discrimination index (D), indicating it effectively differentiates between high and low performers. Among the options, B) p = .50, D = .50 best meets these criteria, with a perfectly moderate difficulty and a good discrimination index.

Which of the Following Test Items Is Best (A, B