Information Technology Reference
In-Depth Information
Figure 7.9
The
Linear Models Least Squares
screen.
expose a second drop-down menu for you to specify the
Confidence
level (%)
. Retain the default of
95
.
Ignore the
Covariates
drop-down menu because there is no covariate
in the analysis.
When you have completed all of these specifications, your screen
should be configured as shown in Figure 7.10. Click
Run
to perform
the analysis.
7.13 THE TUKEY HSD OUTPUT FROM SAS
The output is shown in Figure 7.11. In the top table, the group designation
from the data file occupies the first column and the group means are
provided in the second column. Note that SAS has given its own internal-
for-the-analysis code numbers to the groups in the third column. It is these
code numbers that are used in the bottom table shown in Figure 7.11.
The bottom table in Figure 7.11 displays the results of the pairwise
comparisons of the group means. For example, the entry of .0276 for row 1
(the zero month study group) and column 2 (the two month study group)
is the
p
value for this comparison. This is the same value shown by SPSS
(it was .028), and indicates that the difference between these two means is
statistically significant. As we have already seen from the SPSS analysis, all
mean differences except that between the last two groups are significant.