(1) STUDY DESIGN: This is an experimental study with pre-test and post-test samples in two independent groups. The outcome variable (MIQ) is continuous . We might want to (a) compare the groups at baseline, (b) see if there has been a significant change within groups, and (c) compare the change in MIQ between the two groups at 12 weeks of follow-up.
(2) DATA ENTRY AND VALIDATION: Create data file MONKEY2.MDB. Create file MONKEY-DD.TXT to document these data.
(3) COMPARISON OF GROUPS AT BASELINE
Group 1: mean = 103.0, s = 9.2, n =6
Group 2: mean = 102.7, s = 9.6, n =6
In testing H0: s1 = s2 with Bartlett's test (let a = .05), we find c2stat = 0.01, df = 1, p = .92 (NS)
In testing H0: �1 = �2 with an independent t test (let a = .05), we find tstat= 0.06, df = 10, p = .95 (NS)
(4) CHANGE WITHIN GROUP 1
Mean = 2.5, s = 1.9, n = 6
In testing H0: �d = 0 with a paired t test (let a = .05), we find tstat = 3.27 with 5 df, p = .022. Therefore, there has been a significant increase in MIQ.
(5) CHANGE WITHIN GROUP 2
Mean = 2.0, s = 3.5, n = 6
In testing H0: �d = 0 with a paired t test (let a = .05), we find tstat = 1.38 with 5 df, p = .22. Therefore, retain the null hypothesis.
(6) COMPARISON OF THE CHANGE WITHIN GROUPS AFTER 12 WEEKS OF TREATMENT
Group 1: mean = 2.5, s = 1.9, n =6
Group 2: mean = 2.0, s = 2.5, n =6
In testing H0: s1 = s2 with Bartlett's test (let a = .05), we find c2stat = 1.71, df = 1, p = .19 (NS)
In testing H0: �1 = �2 with an independent t test (let a = .05), we find tstat= 0.31, df = 10, p = .77 (NS)