A clinical researcher was interested in determining whether her interventions for depression were effective in minimizing depression symptoms among her participants.To assess the effectiveness of her treatment program, she administered a depression inventory prior to treatment and after treatment.She hypothesized that depression scores would be lower at time two compared to time one.She then compared the mean differences between the two groups and found that her treatment was effective.Which statistical test was the researcher MOST likely to have used to test her hypothesis?
A) single-sample t test
B) z test
C) independent-samples t test
D) paired-samples t test

Question

Quizplus · Accepted Answer

The researcher administered the depression inventory to the same group of participants twice, before and after the treatment, so the appropriate statistical test is the paired-samples t test, which compares the means of two related groups. The single-sample t test is used to compare the mean of one group to a known or hypothesized value. The z test is used when the population standard deviation is known. The independent-samples t test is used to compare the means of two independent groups.

A Clinical Researcher Was Interested in Determining Whether Her Interventions