In: Statistics and Probability
The following data represent the results from an independent-measures experiment comparing three treatment conditions with n=4n=4 in each sample. Conduct an analysis of variance with α=0.05α=0.05 to determine whether these data are sufficient to conclude that there are significant differences between the treatments.
Treatment A | Treatment B | Treatment C |
---|---|---|
7 | 4 | 6 |
7 | 6 | 5 |
3 | 6 | 8 |
3 | 8 | 9 |
F-ratio =
p-value =
Conclusion:
η2=η2=
To calculate η2η2 you can find the directions in the Learning Activities for Module 16. The directions are within the paragraph that starts with "Another value that sometimes gets calculated..."
The results above were obtained because the sample means are
close together. To construct the data set below, the same scores
from above were used, then the size of the mean differences were
increased. In particular, the first treatment scores were lowered
by 2 points, and the third treatment scores were raised by 2
points. As a result, the three sample means are now much more
spread out.
Before you begin the calculation, predict how the changes in the
data should influence the outcome of the analysis. That is, how
will the F-ratio for these data compare with the
F-ratio from above?
Treatment A | Treatment B | Treatment C |
---|---|---|
5 | 4 | 8 |
5 | 6 | 7 |
1 | 6 | 10 |
1 | 8 | 11 |
F-ratio =
p-value =
Conclusion:
η2=η2=