Q2. Perform and Interpret a Two-Way ANOVA

With this factorial ANOVA, we would like to know:

-Is drug typa significant factor in depression score change?

-Is the episode typa significant factor in depression score change?

-Is there a significant interaction between drugtyp and episodetyp in terms of depression score change?

B. The omnibus effect of the whole factorial ANOVA model.

1. Report the omnibus Ftest result in A- P -A including F, p, and partialh².

2. Draw a conclusion from the hypothesis testing result and state the finding as supported by the result.

C. The main effect of Drugtyp.

1. Report the test result on this main effect in A- P -A, including F, p, and partialh².

2. Draw a conclusion from the hypothesis testing result (reject or fail to reject the null) and state the finding supported by the result.

-Finding must indicate HOW the factor affects the DV if it is a significant effect.

3. bar graph and paste it to show the mean comparison within the main effect. Explain what the graph shows in terms of the main effect.

D. The main effect of Episode typ.

1. Report the test result on this main effect in A- P -A, including F, p, and partialh²

2. Draw a conclusion from the hypothesis testing result (reject or fail to reject the null) and state the finding supported by the result.

-Finding must indicate HOW the factor affects the DV if it is a significant effect.

3.bar graph and paste it to show the mean comparison within the main effect. Explain what the graph shows in terms of the main effect.

E. The Drug x Episode interaction effect from the ANOVA.

1. Report the test result on the interaction effect in A- P -A including F, p, and partialh².

2. Draw a conclusion from the hypothesis testing result (reject or fail to reject the null hypothesis) and state the finding supported by the result.

-the finding should indicate HOW the two factors interact with each other.

3. mean plot with Drug as the horizontal axis and Episode as the grouping factor (for separate lines) and paste it here. Explain what the graph tells us about the interaction.Then describe how the graph shows the (significant or non-significant) interaction.

Data:

Subject ID	Drug	Episode	Dchange
1	1	1	-5
2	1	1	-2
3	1	1	-1
4	1	1	-4
5	1	1	-2
6	2	1	-2
7	1	1	-1
8	2	2	-3
9	1	1	1
10	1	1	-2
11	1	2	-4
12	1	1	-5
13	2	2	-1
14	2	2	-1
15	2	1	-5
16	2	2	1
17	2	1	3
18	2	1	1
19	2	2	-3
20	2	1	-1
21	2	1	-2
22	1	1	-2
23	2	2	3
24	2	2	-2
25	1	2	1
26	1	2	-5
27	1	2	1
28	2	2	-2
29	2	2	0
30	2	2	-1
31	2	1	4
32	1	2	3
33	1	2	-5
34	1	1	-3
35	1	2	-1
36	1	2	4
37	1	1	-4
38	2	2	-1
39	2	1	2
40	2	2	1
41	1	2	-1
42	1	1	-4
43	2	1	0
44	1	2	-3
45	2	1	3
46	1	2	4
47	1	2	-3
48	1	2	-5
49	1	1	-2
50	2	1	0
51	2	1	0
52	2	2	2
53	1	1	-3
54	2	2	-4
55	1	2	0
56	2	2	-3
57	1	2	4
58	2	1	4

Q2
Drug	Type of SSRI (a common antidepressant drug)	1=SSRI 1
		2=SSRI 2
Episode	First or repeated episode of depression	1=first episode
		2=repeated episode
Dchange	Depression score change after drug treatment for 1 month	Depression score (post-treatment minus pre-treatment): Positive means higher level of depression after treatment, negative means lower level of depression after treatment