Nonorthogonal Factorial Designs via SPSS point and click
The following hypothetical salary data represents a nonorthogonal two-by-two factorial design. The first factor (sex) is crossed with college (degree or no degree). The primary question of interest is whether or not there is sex discrimination in terms of salary.
1. The analysis of the data given in Table 7.15 precedes in the typical way for factorial ANOVAs, that is, by making use of the SPSS univariate GLM procedure (recall the univariate procedure is available by clicking Analyze, then General Linear Model, and then Univariate). Because there are unequal sample sizes in the cells, the sums of squares can be decomposed in different ways (as formally explained in Tables 7.19 through 7.22).
2. At this point one can select the desired sums of squares by first clicking the Model button, and then clicking the Sums of Squares button (bottom left of the Univariate: Model window) to select the desired type of sums of squares.
3. At this point clicking Continue on the Univariate: Model window and then OK in the Univariate window will produce the desired results.
Note: for the effect entered first into the Fixed Factor(s) box can make a difference. For example, if the effect “A” is entered into the first effect entered into the Fixed Factor(s) box, the analysis actually performed is a “Type I sums of squares where ‘A’ is entered into the equation first.”