col 1 col 2 col 3 col 4 col 5 41 44 46 43 42 44 46 43 42 41 46 43 42 41 44 43 42 41 44 46 42 41 44 46 43To run ANOVA: Choose Statistics, then Compare Many Groups, OneWay ANOVA. Then choose your data columns just as you did for a t-test, except that you should have choosen five columns. When you are done, click on Finish. Another window will come up asking you about a range test. For now, ignore this and click on Finish. The output is given below.
One Way Analysis of Variance Wednesday, July 21, 1999, 09:13:14 Data source: Data 1 in Notebook Normality Test: Passed (P = 0.216) Equal Variance Test: Passed (P = 1.000) Group N Missing Col 1 5 0 Col 2 5 0 Col 3 5 0 Col 4 5 0 Col 5 5 0 Group Mean Std Dev SEM Col 1 43.200 1.924 0.860 Col 2 43.200 1.924 0.860 Col 3 43.200 1.924 0.860 Col 4 43.200 1.924 0.860 Col 5 43.200 1.924 0.860 Power of performed test with alpha = 0.050: 0.050 The power of the performed test (0.050) is below the desired power of 0.800. You should interpret the negative findings cautiously. Source of Variation DF SS MS F P Between Treatments 4 0.000 0.000 0.000 1.000 Residual 20 74.000 3.700 Total 24 74.000 The differences in the mean values among the treatment groups are not great enough to exclude the possibility that the difference is due to random sampling variability; there is not a statistically significant difference (P = 1.000). |
col 1 col 2 col 3 col 4 col 5 41 45 45 53 32 44 47 42 52 31 46 44 41 51 34 43 43 40 54 36 42 42 43 56 33Rerun the analysis as above.
One Way Analysis of Variance Wednesday, July 21, 1999, 09:16:08 Data source: Data 1 in Notebook Normality Test: Passed (P = 0.216) Equal Variance Test: Passed (P = 1.000) Group N Missing Col 1 5 0 Col 2 5 0 Col 3 5 0 Col 4 5 0 Col 5 5 0 Group Mean Std Dev SEM Col 1 43.200 1.924 0.860 Col 2 44.200 1.924 0.860 Col 3 42.200 1.924 0.860 Col 4 53.200 1.924 0.860 Col 5 33.200 1.924 0.860 Power of performed test with alpha = 0.050: 1.000 Source of Variation DF SS MS F P Between Treatments 4 1010.000 252.500 68.243 <0.001 Residual 20 74.000 3.700 Total 24 1084.000 The differences in the mean values among the treatment groups are greater than would be expected by chance; there is a statistically significant difference (P = <0.001). All Pairwise Multiple Comparison Procedures (Tukey Test): Comparisons for factor: Comparison Diff of Means p q P<0.05 Col 4 vs. Col 5 20.000 5 23.250 Yes Col 4 vs. Col 3 11.000 5 12.787 Yes Col 4 vs. Col 1 10.000 5 11.625 Yes Col 4 vs. Col 2 9.000 5 10.462 Yes Col 2 vs. Col 5 11.000 5 12.787 Yes Col 2 vs. Col 3 2.000 5 2.325 No Col 2 vs. Col 1 1.000 5 1.162 No Col 1 vs. Col 5 10.000 5 11.625 Yes Col 1 vs. Col 3 1.000 5 1.162 No Col 3 vs. Col 5 9.000 5 10.462 Yes |