When you have data on each person in each of two groups, with pretest and posttest measurements for each person in these two different groups, you cannot compute the gain score for each.

Question

Quizplus · Accepted Answer

Gain score is calculated by subtracting pretest score from posttest score for each individual. Therefore, if you have pretest and posttest measurements for each person in two different groups, you can calculate gain score for each group separately.

When You Have Data on Each Person in Each of Two