Predefined Contrasts

Click the Other button in the Contrasts for Dependent Variables dialog box to display the Predefined Contrasts dialog box.

Contrast

Select one of the following predefined contrasts under Contrast:

Deviation

This type of contrast compares the deviations from the grand mean of the dependent variable, for example for a factor with 3 levels, the following matrix of contrasts would be created:

2	-1	-1
-1	2	-1

Difference

This type of contrast compares the levels of a variable with the mean of the preceding levels of that variable, for example for a factor with 3 levels, the following matrix of contrasts would be created:

-1	1	0
-1	-1	2

Helmert

This is the Helmert contrast matrix, for example for a factor with 3 levels, the following matrix of contrasts would be created:

2	-1	-1
0	1	-1

Simple

This type of contrast compares a preceding level of a variable with the last level of that variable, for example for a factor with 3 levels, the following matrix of contrasts would be created:

1	0	-1
0	1	-1

Repeated

This type of contrast compares adjacent levels of a variable, for example for a factor with 3 levels, the following matrix of contrasts would be created:

1	-1	0
0	1	-1

OK

Click the OK button to close the dialog box and return to the Contrasts for Dependent Variables dialog box. The Contrast that you have selected will be entered into the contrast specification columns in this dialog box.

Cancel

Click the Cancel button to close the dialog box and return to the Contrasts for Dependent Variables dialog box, disregarding any changed that you have made.

See also GLM - Index.