Multiple Comparison Procedures - Analysis of Variance Designs - page 162

Figure 7.24 The Contrasts window.

7.28 PERFORMING USER-DEFINED CONTRASTS IN SPSS

Open your data file. From the main menu, select Analyze Compare

➜

Means One-Way ANOVA. That will bring you to the main dialog

window for the procedure as shown earlier in Figure 7.2. Configure it
with group as the Factor and satscore in the Dependent List panel.
Click the Contrasts pushbutton to reach the Contrasts dialog win-
dow shown in Figure 7.24. Make sure that Polynomial is not checked.
We will be using the large middle area where you see Contrast 1 of 1
and a Coefficients panel with the cursor in it. Here is how this window
works:

➜

Contrast 1 of 1 counts our contrasts. We have three of them to
enter. Each contrast will involve us entering the five weights that we
constructed in Table 7.5. We have three contrasts to enter, and we
enter them separately contrast by contrast.
Coefficients has a little panel next to it. This is where you enter the
coefficients or weights that we have constructed in Table 7.5. Focus
on the first contrast. The first weight is 4 and that is what you type
into the little panel. Then click Add . This will transfer the weight into
the large panel in the middle of the window. Type the next weight
(

1) and click Add to transfer this weight into the large panel. As
you do this you will see the weights line up in a column in the large
panel as shown in Figure 7.21. Continue in this manner until you
have finished with the first contrast.

−

SPSS will keep track of the total of the coefficients as you enter them.
When you have finished with the first contrast, you should verify
that the Coefficient Total is 0. This means you have correctly input