A Clinical Psychologist Is Interested in Comparing the Effectiveness of Short

Multiple Choice

A clinical psychologist is interested in comparing the effectiveness of short term relaxation and cognitive-behavioral therapy in treating mild depression. An experiment is conducted in which 15 patients with mild depression are randomly selected and assigned 5 each to a relaxation therapy group, a cognitive/behavioral therapy group, and an attention placebo group. Therapy is administered until the patient is judged no longer depressed or until 10 treatment sessions have elapsed. The following data is obtained. Scores are the number of sessions for each patient. Assume you wanted to compare cognitive/behavioral therapy with relaxation therapy, using planned comparisons and a nondirectional H 1 . The obtained value of the appropriate statistic is _________.

A) Q _obt = 3.15
B) t _obt= -2.29
C) t _obt = -2.22
D) t _obt = -0.55