NAME ______
Dr. Perky U. Upp runs a study looking at the short-term and long term effects effectiveness of three types of therapy for depression; Drug (SSRIs) Therapy, Cognitive Therapy, and a combination of Drug and Cognitive therapy. Depression is measured using a Depression inventory which measures depression on a scale of 0 to 100. Higher numbers indicate higher levels of depression. Participants are randomly assigned to one of the three treatment conditions. Each participant completes the Depression inventory before they begin therapy (pretest); again after completing a 6 month course of treatment (posttest) and again 6 months following therapy (follow-up).
a) What is the dependent variable? (1 point)
b) What are the factors?
c) What is the design of this study?
d) Fully interpret the main effects, interaction and simple main effects for this study. Report F and ps where appropriate.
e) Write a sentence of two that summary the results of this study.
Treatment / Condition / Mean / Std. Deviation / N /
pretest / Drug / 78.6400 / 11.50681 / 25 /
Cognitive / 75.0000 / 11.67262 / 25 /
Drug and Cognitive / 81.6000 / 10.02081 / 25 /
Total / 78.4133 / 11.27314 / 75 /
posttest / Drug / 49.8000 / 14.81834 / 25 /
Cognitive / 60.6000 / 14.45395 / 25 /
Drug and Cognitive / 65.8000 / 13.48456 / 25 /
Total / 58.7333 / 15.58701 / 75 /
Follow-up / Drug / 68.1600 / 12.23274 / 25 /
Cognitive / 53.8000 / 11.15422 / 25 /
Drug and Cognitive / 34.4800 / 7.75199 / 25 /
Total / 52.1467 / 17.36001 / 75 /
Totals / Drug / 65.533 / 1.470 / 25 /
Cognitive / 63.133 / 1.470 / 25 /
Drug and Cognitive / 60.627 / 1.470 / 25 /
Pre-test / Post Test / Follow Up / Totals
SSRI(Drug) / 78.64 / 49.80 / 68.16 / 65.53
Cognitive / 75.00 / 60.60 / 53.80 / 63.13
Combined / 81.60 / 65.80 / 34.48 / 60.62
Totals / 78.41 / 58.73 / 52.15
Two- Way ANOVA
Within Subjects
Source / Sum of Squares / df / Mean Square / F / Sig.Time Periods / 14523.840 / 1 / 14523.840 / 93.915 / .000
Treatment Type * Time Period / 1585.480 / 2 / 792.740 / 5.126 / .008
Error / 11134.680 / 72 / 154.648
Between Subjects
Source / Sum of Squares / df / Mean Square / F / Sig.Treatment Type / 902.99 / 2 / 451.484 / 2.784 / .068
Error / 11676.21 / 72 / 162.170
Post Hoc Tests
LSDs
(I) Type of Treatment / (J) Type of Treatment / Mean Difference (I-J) / Std. Error / Sig.Drug / Cognitive / 2.4000 / 2.07955 / .252
Drug and Cognitive / 4.9067* / 2.07955 / .021
Cognitive / Drug / -2.4000 / 2.07955 / .252
Drug and Cognitive / 2.5067 / 2.07955 / .232
Drug and Cognitive / Drug / -4.9067* / 2.07955 / .021
Cognitive / -2.5067 / 2.07955 / .232
Paired Samples T-TEST
t / df / SigPair 1 / pretest - posttest / 9.192 / 74 / .000
Pair 2 / pretest - followup / 10.719 / 74 / .000
Pair 3 / posttest - followup / 2.141 / 74 / .036
ONE-WAY ANOVA – Pre-Test
Treatment / 546.427 / 2 / 273.213 / 2.221 / .116
Error / 8857.760 / 72 / 123.024
ONE-WAY ANOVA – Post-Test
Source / Sum of Squares / df / Mean Square / F / Sig.Treatment / 3330.667 / 2 / 1665.333 / 8.186 / .001
Error / 14648.00 / 72 / 203.444
ONE-WAY ANOVA – Follow-Up
Source / Sum of Squares / df / Mean Square / F / Sig.Treatment / 14281.79 / 2 / 7140.893 / 64.111 / .000
Error / 8019.600 / 72 / 111.383
POST HOCs
PRE-TEST LSDs
(I) Type of Treatment / (J) Type of Treatment / Mean Difference (I-J) / Std. Error / Sig.Drug / Cognitive / 3.6400 / 3.13719 / .250
Drug and Cognitive / -2.9600 / 3.13719 / .349
Cognitive / Drug / -3.6400 / 3.13719 / .250
Drug and Cognitive / -6.6000* / 3.13719 / .039
Drug and Cognitive / Drug / 2.9600 / 3.13719 / .349
Cognitive / 6.6000* / 3.13719 / .039
POST-TEST LSDs
Drug / Cognitive / -10.8000* / 4.03430 / .009
Drug and Cognitive / -16.0000* / 4.03430 / .000
Cognitive / Drug / 10.8000* / 4.03430 / .009
Drug and Cognitive / -5.2000 / 4.03430 / .202
Drug and Cognitive / Drug / 16.0000* / 4.03430 / .000
Cognitive / 5.2000 / 4.03430 / .202
FOLLOW-UP LSDs
(I) Type of Treatment / (J) Type of Treatment / Mean Difference (I-J) / Std. Error / Sig.Drug / Cognitive / 14.3600* / 2.98507 / .000
Drug and Cognitive / 33.6800* / 2.98507 / .000
Cognitive / Drug / -14.3600* / 2.98507 / .000
Drug and Cognitive / 19.3200* / 2.98507 / .000
Drug and Cognitive / Drug / -33.6800* / 2.98507 / .000
Cognitive / -19.3200* / 2.98507 / .000