Dr. Jarrar is studying the effect of caffeine on anxiety in college students. Two hundred students are randomly assigned to one of two groups. The first group drinks 5 cups of caffeinated coffee, then completes an Anxiety scale. The second group drinks 5 cups of decaffeinated coffee; then completes same scale. Scores on the Anxiety scale are then compared for the 2 groups to see if there is a difference. In this experiment, the Anxiety scales scores are the ____________