The model describes the way in which the response and factors are to be related to each other. The following standard models are available:
You can also build your own model. Note that not all models are available for all analyses. For example, a main effects only model is always used in simple linear regression and one-way analysis of variance.
When you press the button, you are prompted for the model if a model has not already been specified. You can also specify or change the model by selecting 'Change' and then 'Model...' from the Locals pull-down menu, or by selecting the keyword 'Model:' in the body of the main window.