GDA Effects in Design

Click the Effects in Design button on the GDA Quick Specs dialog box - Quick tab to display the GDA Effects in Design dialog box, which contains options to specify the effects for the between group design, i.e., for the continuous and categorical predictor variables.

Use default effects for the design

Select the Use default effects for the design option button to dim the options in the Predictor Variables, Method, and Effects in the design group boxes (see below). In that case, the respective default design will be created for the current categorical and continuous predictor variables (e.g., a full factorial design for the categorical predictors, and main effects only for the continuous predictors).

Use custom effects for the design

Select the Use custom effects for the design option button to specify the specific effects for the selected variables that are to be included in the model. Note that categorical or continuous predictor variables that do not appear in any effect in the Effects in the design group box, but were selected via the Variables button on the GDA Quick Specs dialog box - Quick tab, will automatically be dropped from the analysis (however, they are still included in the check for any missing data!).

OK

Click the OK button after you have specified the effects for the between group design to return to the GDA Quick Specs dialog box - Quick tab.

Cancel

Click the Cancel button to return to the GDA Quick Specs dialog box - Quick tab, ignoring any changes that you have made.

Predictor variables, Method, and Effects in the design

Select the Categorical and/or Continuous predictor variables in the Predictor Variables group box. Next, choose the design for those variables by clicking on the respective button in the Method group box, and the effect(s) will then appear in the Effects in the design group box. To reorder the effects in the Effects in the design group box, first select them (e.g., click on the effect or list of effects), then move the mouse cursor to the desired location in the list, and when the mouse cursor changes to the insertion bar , click the left-mouse button to move the selected effects.

Note: specifying effects for the between group design. The method of specifying the between design is the same as that described in the context of the General Linear Models module, except that you cannot specify any nested effects (because GDA will always use the sigma-restricted parameterization for models that include categorical predictors; see also the Introductory Overview). For complete details about specifying effects for the between group design and the specific options in the Predictor Variables, Method, and Effects in the design group boxes, see Specifying Effects for the Between Group Design.

See also GDA - Index.