12. Measuring effect size for two-factor ANOVA
It is projected that approximately 580,000 veterans will take advantage of the GI Bill for the 21st Century. Boots to Books is a course for all veterans, current military members, and their family members, friends, and supporters. The goal of Boots to Books is to assist deployed, postdeployed, and veteran students in making a positive transition from military to civilian life or from deployment to postdeployment life, including the acquisition of college survival skills.
Posttraumatic stress disorder (PTSD) is quite common among combat veterans. Suppose that a researcher wants to revise the Boots to Books course in order to reduce the effects of PTSD. He recruits a group of combat veterans and collects data on the length of time they were in the military (factor A) and the potential components of the revised course (journaling, community service, physical activity, and meditation: factor B). He then assigns them one of the four components. The study will evaluate which components of the program are the most effective for reducing PTSD symptoms.
The results of the hypothetical study are summarized in the following data matrix. Each cell reports the average (M), the total (T), and the sum of squares (SS) of the symptom score (X) on the Clinician-Administered PTSD Scale (CAPS) of 10 veterans. Veterans are grouped according to the number of years they served in the military.
The results of the hypothetical study are summarized in the following data matrix. Each cell reports the average (M), the total (T), and the sum of squares (SS) of the symptom score (X) on the Clinician-Administered PTSD Scale (CAPS) of 10 veterans. Veterans are grouped according to the number of years they served in the military.
Factor B: Program Component
Journaling |
Community Service |
Physical Activity |
Meditation |
||||
---|---|---|---|---|---|---|---|
M = 36.5 | M = 39 | M = 42 | M = 45 | ||||
1–2 | T = 365 | T = 390 | T = 420 | T = 450 | TROW1 |
= 1,625 | |||||||
SS = 252.5 | SS = 840 | SS = 460 | SS = 350 | ||||
Factor A: Years in Military | ΣX² = 156,870 | ||||||
M = 44 | M = 44.8 | M = 47.6 | M = 49.1 | ||||
3–4 | T = 440 | T = 448 | T = 476 | T = 491 | TROW2 |
= 1,855 | |||||||
SS = 840 | SS = 743.6 | SS = 670.4 | SS = 644.9 | ||||
TCOL1 |
= 805 | TCOL2 |
= 838 | TCOL3 |
= 896 | TCOL4 |
= 941 |
The researcher performs an analysis of variance (ANOVA) to test the hypothesis that the populations defined by the treatment combinations are equal. The results are presented in the following ANOVA table.
ANOVA Table
Source |
SS |
df |
MS |
F |
---|---|---|---|---|
Between treatments | 1,238.6000 | 7 | ||
Factor A | 661.2520 | 1 | 661.2520 | 11.20 |
Factor B | 548.3000 | 3 | 182.7667 | 3.10 |
AXB interaction | 29.0480 | 3 | 9.6827 | 0.16 |
Within treatments | 4,251.4000 | 72 | 59.0472 | |
Total | 5,490.0000 | 79 |
Use the significance level α = 0.05 to complete the following conclusions.
1. The critical F value for factor A (years in military) is __________. Therefore, the main effect due to factor A ____________ (significant/not significant) .
2. The critical F value for factor B (program component) is ____. Therefore, the main effect due to factor B _________ (significant/not significant).
The critical F value for the interaction of factors A and B is _______. Therefore, the effect due to the interaction of factors A and B is ______________ (significant/not significant) .
Given the results of the preceding analysis, what does the researcher conclude? (pick one_)
a. Veterans who took different components of the program had different PTSD symptom scores. The severity of PTSD symptoms was unrelated to length of service either by itself or in conjunction with the various components of the program.
b. Veterans with different lengths of service had different PTSD symptom scores. The severity of PTSD symptoms was unrelated to program component either by itself or in conjunction with length of service.
c.Length of service and program component were each related to the severity of PTSD symptoms. However, the effect of each factor was independent of the other.
d. Neither length of service nor program component was related to the severity of PTSD symptoms when looked at alone. However, there was an interaction between the two factors such that severity differed by program component differently depending on length of service (and vice versa).
Measure the effect size for factor A (years in military), factor B (program component), and the interaction by computing (partial) eta squares. (Express the value of each eta square as a percent.)
η² for factor A (years in military) = _______
η² for factor B (program component) =______
η² for the interaction =_______
12. Measuring effect size for two-factor ANOVA It is projected that approximately 580,000 veteran...
12. Measuring effect size for two-factor ANOVA It is projected that approximately 580,000 veterans will take advantage of the GI Bill for the 21st Century. Boots to Books is a course for all veterans, current military members, and their family members, friends, and supporters. The goal of Boots to Books is to assist deployed, postdeployed, and veteran students in making a positive transition from military to civilian life or from deployment to postdeployment life, including the acquisition of college survival...
4. Measuring effect size for two-factor ANOVA Аа Аа It is projected that approximately 580,000 veterans will take advantage of the GI Bill for the 21st Century. Boots to Books is a course for all veterans, current military members, and their family members, friends, and supporters. The goal of Boots to Books is to assist deployed, postdeployed, and veteran students in making a positive transition from military to civilian life or from deployment to postdeployment life, including the acquisition of...
It is projected that approximately 580,000 veterans will take advantage of the Gt Bill for the 21st Century. Boots to Books is a course for all veterans, current military members, and their family members, friends, and supporters. The goal of Boots to Books is to assist deployed, postdeployed, and veteran students in making a positive transition from military to civilian life or from deployment to postdeployment life, including the acquisition of college survival skills. Post-traumatic stress disorder (PTSD) is quite...
Do Chapter 13 End-of-Chapter Problems It is projected that approximately 580,000 veterans will take advantage of the GI Bill for the 21st Century. Boots to Books is a course for all veterans, current military members, and their family members, friends, and supporters. The goal of Boots to Books is to assist deployed, postdeployed, and veteran students in making a positive transition from military to civilian life or from deployment to postdeployment life, including the acquisition of college survival skills Post-traumatic...
Attempts: Average: /15 Д 4. Determining main effects and interactions in a two-way ANOVA А. Аа It is projected that approximately 580,000 veterans will take advantage of the GI Bill for the 21st Century. Boots to Books is a course for all veterans, current military members, and their family members, friends, and supporters. The goal of Boots to Books is to assist deployed, postdeployed, and veteran students in making a positive transition from military to civilian life or from deployment...
need help with all m/af/serviet/quiztuizaction 12ckom 1555252849687 0AAABBEE016 8. Measuring effect size for factorial ANOVA Consider the results of a study in which a researcher is interested in the combination of drug types and behavioral therapies for relieving exercise regime) and antidepressants (FeelGood, Cheerup, Energize, and SadNoMore). The researcher defines the first factor as the Aa Aa symptoms. The researcher assigns patients to different types of behavioral programs (cognitive behavioral therapy or reguilar behavioral program and the second factor as...
The following results are from an independent-measures, two-factor study with n condition. 10 participants in each treatment Factor B Factor A 2 T 40 M=4.00 SS = 50 T=50 M = 5.00 SS = 60 T= 10 M 1.00 SS 30 T=20 M 2.00 SS 40 N = 40; G = 120; Σ? = 640 Use a two-factor ANOVA with α =。05 to evaluate the main effects and the interaction Source df MS Between treatments AxB Within treatments Total For...
The following results are from an independent-measures, two-factor study with n = 5 participants in each treatment condition Factor A: Factor B: 3 M=5 M=8 M=14 T=25 T=40 T=70 SS 30 SS 38 SS46 n=5 n=5 n=5 2 T= 15 T-20 T=40 SS 22 SS 26 SS 30 ZX2 = 2,062 Use a two-factor ANOVA with α = .05 to evaluate the main effects and interaction. Source df MS Between treatments A x B Within treatments Total F Distribution Numerator...
Aa Aa 11. Two-factor ANOVA Emphasis on calculations W.Thomas Boyce, a professor and pediatrician at the University of British Columbia, Vancouver, has studied interactions between individual differences in physiology and differences in experience in determining health and well-being. Dr. Boyce found that some children are more sensitive to their environments. They do exceptionally wel when the environment is suppo「tive but are much more likely to have mental and physical health problems when the environment has challenges. You decide to do...
3. Two-factor analysis of variance Emphasis on calculations Aa Aa W. Thomas Boyce, a professor and pediatrician at the University of British Columbia, Vancouver, has studied interactions between individual differences in physiology and differences in experience in determining health and well-being. Dr. Boyce found that some children are more sensitive to their environments. They do exceptionally well when the environment is supportive but are much more likely to have mental and physical health problems when the environment has challenges You...