Final answer:
The psychologist in this experimental study uses the experimental method to determine whether group therapy is as effective as individual therapy in treating test anxiety.
Step-by-step explanation:
The psychologist in this experimental study is using the experimental method to determine whether group therapy is as effective as individual therapy in treating test anxiety. In this study, the type of therapy (group therapy or individual therapy) is the independent variable. The psychologist manipulates this variable by assigning participants to either the group therapy or individual therapy condition. The effectiveness of the therapy in reducing test anxiety, which is measured by a test anxiety scale, is the dependent variable. This variable is measured to see how the type of therapy (independent variable) impacts the participants' test anxiety levels.