A researcher conducted an experiment on the effects of a new "drug "on depression. The researcher had a control group that received nothing, a placebo group, and an experimental group that received the "drug." A depression inventory that provided a measure of depression on a 50-point scale was used (50 indicates that an individual is very high on the depression variable).
| Source |
df |
SS |
MS |
F |
| Between |
2 |
1,202.30 |
601 |
3.23 |
| Within |
42 |
2,118.00 |
50.42 |
|
| total |
44 |
3,320.31 |
|
|
a. Is Fobt significant at Fobt= .05; at Fobt= .01?
b. Perform post hoc comparisons if necessary.
c. What conclusions can be drawn from the F-ratio and the post hoc comparisons?
d. What is the effect size, and what does this mean?
e. Graph the means.