Dividing the number of persons who answered correctly by the total number of persons who responded to the question is a measure of an item's ______.
A) discrimination index
B) phi coefficient
C) difficulty
D) bias

Question

Quizplus · Accepted Answer

Dividing the number of persons who answered correctly by the total number of persons who responded to the question gives us the difficulty index of the item, which indicates how challenging the item is for the respondents. The discrimination index would require comparing the performance of high and low scorers, the phi coefficient is a measure of association between two dichotomous variables, and bias refers to systematic errors in measurement.

Dividing the Number of Persons Who Answered Correctly by the Total