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Figure 11.3
Data file for the numerical example.
11.7 PERFORMING THE OMNIBUS ANALYSIS IN SPSS
11.7.1 STRUCTURING THE DATA FILE
Thedatafileforatwo-waywithin-subjectsdesignisstructuredinamore
complex fashion than the one-way design. We show in Figure 11.3 the
data file for our 2
3 within-subjects design example. The first column,
as always, is used for our participant identification number; we have
named this variable subid . The next six columns are devoted to the cells
representing our two-way design.
The variables (columns) in the data file are ordered in a systematic
manner so that they will match up with our independent variables. Recall
from Figure 11.1 that the two rows represented the vehicles that the
students were driving and that the three columns represented the number
of drinks the students consumed prior to driving. The first cell in this 2
×
3
matrix coincides with column 2 in the data file with the variable name
car0 . It refers to students driving sports cars (the first level of vehicle )
with no alcohol consumed (the first level of drinks ). In our design matrix
in Figure 11.1, it is the upper left cell. The next two columns are named
car1 and car3 . These cells also refer to the first level of vehicle (sports car)
but step us through the remaining levels of drinks .Thus, car1 denotes
the driving errors for sports cars with students having had one drink
whereas car3 denotes the errors for sports cars with students having had
three drinks.
The next three columns in the data file step us through the second level
of Vehicle: suv0 , suv1 , and suv3 represent the cells for students driving an
SUV after zero, one, or three drinks. Note that we use the same structure
here as we did for the sports car level of Vehicle .Inthisstructure,asweview
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