Error Terms for Individual Effects (MANOVA: Univariate command)

The “error” sum of squares against which terms in the design are tested is specified on the ERROR subcommand. For any particular term on a DESIGN subcommand, you can specify a different error term to be used in the analysis of variance. To do so, name the term followed by the keyword VS (or AGAINST) and the error term keyword.

To test a term against only the within-cells sum of squares, specify the term followed by VS WITHIN on the DESIGN subcommand. For example, GROUP VS WITHIN tests the effect of the factor GROUP against only the within-cells sum of squares. For most analyses, this term is the default error term.
To test a term against only the residual sum of squares (the sum of squares for all terms that are not included in your DESIGN), specify the term followed by VS RESIDUAL.
To test against the combined within-cells and residual sums of squares, specify the term followed by VS WITHIN+RESIDUAL.
To test against any other sum of squares in the analysis of variance, include a term corresponding to the desired sum of squares in the design and assign it to an integer between 1 and 10. You can then test against the number of the error term. It is often convenient to test against the term before you define it. This process is perfectly acceptable as long as you define the error term on the same DESIGN subcommand.

Example

MANOVA DEP BY A, B, C (1,3)
  /DESIGN=A VS 1,
          B WITHIN A = 1 VS 2,
          C WITHIN B WITHIN A = 2 VS WITHIN.

In this example, the factors A, B, and C are completely nested; levels of C occur within levels of B, which occur within levels of A. Each factor is tested against everything within it.
A, the outermost factor, is tested against the B within A sum of squares, to see if it contributes anything beyond the effects of B within each of its levels. The B within A sum of squares is defined as error term number 1.
B nested within A, in turn, is tested against error term number 2, which is defined as the C within B within A sum of squares.
Finally, C nested within B nested within A is tested against the within-cells sum of squares.

User-defined error terms are specified by simply inserting = n after a term, where n is an integer from 1 to 10. The equals sign is required. Keywords that are used in building a design term, such as BY or WITHIN, are evaluated first. For example, error term number 2 in the above example consists of the entire term C WITHIN B WITHIN A. An error-term number, but not an error-term definition, can follow the keyword VS.