Define Perform a single factor ANOVA.
ANOVA Study Aggression
Katie is learning aggression among adolescent girls. She trusts that there is a relationship between the level of interaction a girl has with her mother and her level of aggression. She has recognised 5 girls who fall into each of 4 interaction levels and has measured their aggression scores. Her data are given below.
No Interaction

Low Interaction

Moderate Interaction

High Interaction

4

4

4

3

5

6

4

4

6

5

3

4

6

4

5

3

5

5

4

3

The instant table is as follows:
Source

Sum of Squares

df

Mean Square

F

Between groups

9.75

3

3.250

5.91

Within groups

8.80

16

0.550


Total

18.55

19



1) What are the independent variable and the dependent variables?
2) Should Katie conduct betweensubjects ANOVA or a withinsubjects ANOVA? describe your answer.
3) How many factors are involved in Katie's study?
4) How many levels are involved? Name the level(s).
5) What are the null and alternate hypotheses?
6) Using α = 0.05, what is F_{crit}?
7) Is the Ftest significant?
8) Based on your answer about significance, what else should you do and why?