Patients are randomly assigned to undergo psychotherapy or b

Patients are randomly assigned to undergo psychotherapy or behavioral therapy. After 20 therapeutic sessions, each patient takes a mental health questionnaire. What test would be used to see if there are differences in mental health at the end of therapy?

(a) z test

(b) t test for one sample

(c) t test for two independent samples

(d) t test for two related samples

Solution

This is clearly paired t test as the same patients take 2 tests.

(d) t test for two related samples