A psychologist randomly divides patients experiencing social anxiety into three groups, each of which receives a different treatment believed to reduce social anxiety. A research assistant, who knows nothing about the study, measures each patient’s level of social anxiety using a standard questionnaire once before and once after their treatment. The psychologist analyzes the data afterwards, and finds that group 3 is the only group who showed a reduction in their social anxiety scores, from pre-treatment to post-treatment.

a.    Is this an experiment? Why or why not?

b.    Identify the independent and dependent variables.

c.   How are potential confounds minimized in this design? Explain your answer.

d.    Can the psychologist conclude that the treatment administered to Group 3 caused a reduction in their social anxiety scores? Justify your answer.