STAT 529
Multiple Comparisons
The following output shows all pairwise comparisons (6 pairs) for the birthweight data,
controlling the familywise error rate at most 5% (familywise confidence level at least 95%) by
Tukey-Kramer method and Bonferroni method.
One-way ANOVA: Birthweight versus Smoking
Analysis of Variance for Birthwei
Source DF SS MS F P
Smoking 3 11.673 3.891 4.41 0.014
Error 23 20.304 0.883
Total 26 31.976
Individual 95% CIs For Mean
Based on Pooled StDev
Level N Mean StDev -------+---------+---------+---------
1 7 7.5857 0.9616 (------*------)
2 5 7.2400 0.9127 (-------*--------)
3 7 6.3286 1.1398 (------*-------)
4 8 6.0125 0.7200 (------*------)
-------+---------+---------+---------
Pooled StDev = 0.9396 6.0 7.0 8.0
1) Tukey-Kramer method
Tukey 95% Simultaneous Confidence Intervals
All Pairwise Comparisons among Levels of Smoking
Individual confidence level = 98.90%
Smoking = 1 subtracted from:
Smoking Lower Center Upper ---------+---------+---------+---------+
2 -1.8668 -0.3457 1.1753 (---------*---------)
3 -2.6457 -1.2571 0.1314 (---------*--------)
4 -2.9176 -1.5732 -0.2288 (--------*-------)
---------+---------+---------+---------+
-1.5 0.0 1.5 3.0
Smoking = 2 subtracted from:
Smoking Lower Center Upper ---------+---------+---------+---------+
3 -2.4325 -0.9114 0.6096 (---------*---------)
4 -2.7084 -1.2275 0.2534 (---------*---------)
---------+---------+---------+---------+
-1.5 0.0 1.5 3.0
Smoking = 3 subtracted from:
Smoking Lower Center Upper ---------+---------+---------+---------+
4 -1.6605 -0.3161 1.0284 (--------*--------)
---------+---------+---------+---------+
-1.5 0.0 1.5 3.0
