In: Statistics and Probability
Answer the within-subjects ANOVA questions using the data below.
Use α = 0.01.
| 1 | 2 | 3 | 4 |
|---|---|---|---|
| 53 49 47 42 51 39 44 |
44 39 36 34 39 30 29 |
46 42 39 37 36 34 26 |
44 35 30 27 33 28 31 |
Compute the corresponding effect size(s) and indicate
magnitude(s).
η2 = ; ---Select--- na
trivial effect small effect medium effect large effect
Conduct Scheffe's Post Hoc Test for the following
comparisons:
1 vs. 4: test statistic = ;
significant: ---Select--- Yes No
2 vs. 3: test statistic = ;
significant: ---Select--- Yes No
Anova: Single Factor
| SUMMARY | ||||
| Groups | Count | Sum | Average | Variance |
| 1 | 7 | 325 | 46.42857 | 25.28571 |
| 2 | 7 | 251 | 35.85714 | 28.47619 |
| 3 | 7 | 260 | 37.14286 | 40.14286 |
| 4 | 7 | 228 | 32.57143 | 32.95238 |
| ANOVA | ||||||
| Source of Variation | SS | df | MS | F | P-value | F crit |
| Between Groups | 740.8571 | 3 | 246.9524 | 7.786787 | 0.000843 | 4.718051 |
| Within Groups | 761.1429 | 24 | 31.71429 | |||
| Total | 1502 | 27 |
effect size = (SSbetween groups) / (SSTotal) = 740.8571/ 1502 = 0.493, effect size is large.
Scheffe's Post Hoc Test
| treatments pair | Scheffé T -statistic | Scheffé p-value | Scheffé inferfence |
| 1 vs 2 | 3.5119 | 0.017341 | * p<0.05 |
| 1 vs 3 | 3.0848 | 0.042538 | * p<0.05 |
| 1 vs 4 | 4.6034 | 0.001447 | ** p<0.01 |
|
2 vs 3 |
0.4271 | 0.979901 | insignificant |
| 2 vs 4 | 1.0915 | 0.756237 | insignificant |
| 3 vs 4 | 1.5187 | 0.522777 | insignificant |
1 vs. 4: test statistic = 4.6034 ; significant:Yes
2 vs. 3: test statistic = 0.4271 ;
significant: No