You can use the **Variables** tab to specify the variables for the Generalized Linear Models analysis. The **Variables** tab is shown in Figure 24.6.

For most response distributions, you only need to specify a single response variable in the *events*).
The value of the second variable is the number of *trials*.
In this case, the response distribution is automatically set to binomial.

The dialog box supports multiple explanatory variables. You can include nominal variables in the model by adding them to the You can include interval variables in the model by adding them to the list.

list.When you add an explanatory variable, that main effect is added to the **Effects** tab. You can add interaction effects and nested effects by using the **Effects** tab.