How Do Researchers Calculate the Discrimination Index

Multiple Choice

How do researchers calculate the discrimination index?

A) They calculate the difference between the percentage of upper performers and the percentage of lower performers who responded correctly.
B) They calculate the percentage of test takers who answered the item correctly.
C) They compare the percentage of test takers who answered the item correctly by demographic group.
D) They develop a matrix that contains the results of the item analyses for each item and calculate a score by adding the matrix columns.