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Figure 7.7
The
Linear Models Task Roles
window.
mean difference this large being found if the null hypothesis is true. The
value of .028 is less than our alpha value of .05, and so we judge that the
two groups differ significantly.
As we scan down the
Sig.
column, we note that all of the pairwise
comparisons are statistically significant except for the pairing of the six
month and eight month study groups, where we find a value of .992 for
the probability of that much of a difference occurring by chance alone,
assuming that the null hypothesis is true. This is, of course, what we
have already learned from the display of homogeneous subsets. These two
displays are just based on different formats and levels of detail to present
the same Tukey results, and students can work with whichever they are
more comfortable.
7.12 PERFORMING A TUKEY HSD TEST IN SAS
Import your data from Excel into a new project or open
SAS Enterprise
Guide
projectforChapter6.Wewillassumethatyoualreadyhavethe
descriptive statistics for the groups and so will deal directly with per-
forming the Tukey post hoc test. From the main menu select
Analyze
➜
ANOVA
Linear Models.
On the
Task Roles
tab, specify
satscore
as
the
Dependent variable
and
group
as the
Classification variable
.Thisis
shown in Figure 7.7.
➜
