Variable Selection

When using either forward or backward stepwise multiple regression a dialog box is displayed to enable you to select the species against which you wish to test your environmental variables. With forward stepwise regression, the dialog has boxes for you to enter and adjust the minimum probabilities required to enter variables into the model and to remove them again if they have little value (thereby preventing all variables from being entered, and complicating the model).

Click OK to run the analysis and display the results on the Regression tab.

With backward stepwise regression, because variables are removed, rather than being added there is no minimum probability for removal and thus the probability boxes are not displayed.

Click OK to run the analysis and display the results on the Regression tab.