Review the five steps of hypothesis testing and complete the following problems.
1. Researches are interested in whether depressed people undergoing group therapy will perform a different number of activities of daily living after group therapy. The researchers have randomly selected 12 depressed clients to undergo a 6-week group therapy program.
Use the five steps of hypothesis testing to determine whether the average number of activities of daily living (shown below) obtained after therapy is significantly different from a mean number of activities of 14 that is typical for depressed people. (Clearly indicate each step).
Test the difference at the .05 level of significance and, for practice, at the .01 level (in SPSS this means you change the "confidence level" from 95% to 99%).
In Step 2, show all calculations.
As part of Step 5, indicate whether the behavioral scientists should recommend group therapy for all depressed people based on evaluation of the null hypothesis at both levels of significance and calculate the effect size.
CLIENT AFTER THERAPY
A 17
B 15
C 12
D 21
E 16
F 18
G 17
H 14
I 13
J 15
K 12
L 19
2. Researchers are interested in whether depressed people undergoing group therapy will perform a different number of activities of daily living before and after group therapy. The researchers have randomly selected 8 depressed clients in a 6-week group therapy program.
Use the five steps of hypothesis testing to determine whether the observed differences in numbers of activities of daily living (shown below) obtained before and after therapy are statistically significant at the .05 level of significance and, for practice, at the .01 level. (Clearly indicate each step).
In Step 2, show all calculations. As part of Step 5, indicate whether the researchers should recommend group therapy for all depressed people based on evaluation of the null hypothesis at both levels of significance and calculate the effect size.
CLIENT BEFORE THERAPY AFTER THERAPY
A 12 17
B 7 15
C 10 12
D 13 21
E 9 16
F 8 18
G 14 17
H 11 8