Q2. Perform and interpret a t-test with SPSS.(13 points)

A researcher would like to know if memory function changes significantly from the first testing session (Mem1) to the second testing session (Mem2). Perform a two-tailed t-test with = .05 to answer the following question:

Does memory performance change significantly from the first session to the second?

1. What type of t-test should be performed to answer this question? What is your rationale?(1 point, 0.5 points for answer and rationale)

B. Create the null hypothesis from the research question. (2 points - NOTE: students do not need to include both written and symbols)

C. Run the analysis in SPSS and answer the following questions based on the analysis results. (Paste all the output tables from SPSS for this test. No points will be earned for the rest of the questions in Q2 if the output tables are not pasted or are incomplete). (2 points - No points will be earned for the rest of the questions in Q2 if the output tables are not pasted or are incomplete).

D. Use the SPSS output to determine the effect size, Cohen's d,and explain what the effect size means in this context. Effect size must show in the SPSS table. Do not round, report all decimals from the table. (Note: It is OK if d is negative. But it needs to be consistent with the sign of t statistic.)(2 points, 1 point for Cohen's d and 1 point for explanation)

d =

Explanation:

E. Report the t-test result in symbols according to the APA standards, including t statistic with degree of freedom, p-value, and effect size d. (2 points, 0.5 points for each correct value, 0.5 points for proper APA formatting)

t() = , p , d =

F. What is your decision about the null hypothesis (reject or fail to reject)? What is your rationale/reason? (2 points, 1 point for answer and 1 point for the rationale)

G. What is the answer to the research question? (2 points)

SubID	Gender	Educ	Age	Mem1	Mem2
1	1	1	65.8	100.43	95.63
2	1	0	66.9	87.00	90.00
3	1	0	76.9	87.00	90.00
4	1	0	79.9	85.77	79.00
5	1	0	67.5	93.40	90.27
6	1	0	84.1	102.19	101.34
7	1	0	73	98.31	96.20
8	2	1	75.6	112.20	109.74
9	2	0	82.6	109.89	105.76
10	1	0	78	104.75	98.03
11	2	0	66.3	102.19	99.37
12	2	0	65.1	93.70	88.29
13	2	1	67.2	101.30	97.49
14	2	0	70	106.59	100.37
15	2	1	80	84.34	86.44
16	2	0	69.4	99.12	86.93
17	2	0	65.3	107.04	102.36
18	2	1	70.6	94.42	91.44
19	2	0	78.4	112.80	109.91
20	2	1	69.6	93.83	92.43
21	2	1	65.8	102.60	97.34
22	2	0	75	81.45	79.25
23	2	0	68.5	103.55	99.07
24	1	1	69.5	93.13	89.43
25	1	1	67	114.53	112.87
26	2	0	69.9	108.73	103.84
27	2	1	86.6	95.89	94.90
28	2	1	65	80.11	80.88
29	1	0	65.2	92.13	91.85
30	2	0	76.8	111.96	109.24
31	1	0	75.4	106.01	103.08
32	2	1	66.7	113.34	109.89
33	2	0	65.5	110.51	110.02
34	2	1	72.8	102.92	100.72
35	2	1	79.5	100.49	98.43
36	2	0	72.9	108.46	102.21
37	2	1	69.7	115.03	111.08
38	1	1	66	102.62	100.30
39	1	1	72	100.00	103.97
40	1	1	75.8	110.02	111.17
41	1	1	65.4	85.77	81.28
42	2	1	67	97.02	96.76
43	2	1	79.2	108.46	100.26
44	1	1	69.3	101.39	100.42
45	1	1	68.1	83.58	82.74
46	2	0	76	107.63	105.91
47	1	1	67.8	99.51	95.98
48	2	1	73	104.82	101.21
49	1	1	71.9	107.02	103.62
50	2	0	68.3	114.60	109.18