181
Complex Samples General Linear Model
E
Select a Simple contrast and 3 Self and family as the reference category for shopfor. Note that, once
selected, the category appears as “3” in the dialog box.
E Select a Simple contrast and 1Noas the reference category for usecoup.
E Click Continue.
E Click OK in the General Linear Model dialog box.
Model Summary
Figure 19-6
R-square statistic
R-square, the coefficient of determination, is a measure of the strength of the model fit. It shows
that about 60% of the variation in Amount spent is explained by the model, which gives you
good explanatory ability. You may still want to add other predictors to the model to further
improve the fit.
Tests of Model Effects
Figure 19-7
Tests of between-subjects effects
Each term in the model, plus the model as a whole, is tested for w hether the value of its effect
equals 0. Terms with significance values of less than 0.05 have some discernible effect. Thus, all
model ter
ms contribute to the model.
