Comparing two designs (or anything else!) using independent sample T-tests - Improving the User Experience through Practical Data Analytics - page 60

FIGURE 2.7
Data in SPSS format.
In Figure 2.7 , the data actually consist of 38 rows (18 for Design 1 and 20 for
Design 2), but they did not all it on one screen. Note that in the “Design” (VAR00002)
column, the irst 18 entries are “1's”; the next 20 are “2's,” although you can see only
the irst 23 rows.
Next, pull down the “Analyze” menu, choose “Compare Means,” and then “Inde-
pendent Samples t-test,” as per the illustration in Figure 2.8 . See arrows in Figure 2.8 .
Click on “Independent Sample t-test” to produce the dialog box shown in
Figure 2.9 .
As is always the case for SPSS, and as we have seen, all of the variables are listed on
the left. We can enter “Variable View” (in the bottom left of Figure 2.9 ) and rename the
variable 1: Sophistication, and variable 2: Design, or any other names you wish to give.
We now drag “Sophistication” (VAR00001) to the “test variable” box (the variable
or outcome on which we wish to know whether there is a difference) and “Design”