User Guide

373
One-Way ANOVA

Gabriel. Pairwise comparison test that used the Studentized maximum modulus
and is gener
ally more powerful than Hochberg's GT2 when the cell sizes are
unequal. Gabriel's test may become liberal when the cell sizes vary greatly.
 Waller-Duncan. Multiple comparison test based on a t statistic; uses a Bayesian
approach.
 Dunnett. Pairwisemultiplecomparisonttestthatcomparesasetoftreatments
against a si
ngle control mean. The last category is the default control category.
Alternatively, you can choose the first category.
2-sided tests that the mean at any
level (except the control category) of the factor is not equal to that of the control
category.
<Controltests if the mean at any level of the factor is smaller than that
of the control category.
> Control tests if the mean at any level of the factor is
greater than that of the control category.
Equal Var
iances Not Assumed
Multiple
comparison tests that do not assume equal variances are Tamhane’s T2,
Dunnett’s T3, Games-Howell, and Dunnett’s C.
 Tamhane's T2. Conservative pairwise comparisons test based on a t test. This test
is approp
riate when the variances are unequal.
 Dunnett
's T3.
Pairwise comparison test based on the Studentized maximum
modulus. This test is appropriate when the variances are unequal.
 Games-Howell. Pairwise comparison test that is sometimes liberal. This test is
appropriate when the variances are unequal.
 Dunnett's C. Pairwise comparison test based on the Studentized range. This test is
appropr
iate when the variances are unequal.
Note: You may find it easier to interpret the output from post hoc tests if you deselect
Hide empty rows and columns in the Table Properties dialog box (in an activated pivot
table, c
hoose
Table Proper tie s from the Format menu).