Automatic Selection of Best Model

Click the Automatic selection of best model button on the Log-Linear Model Specification dialog box - Quick tab or Advanced tab to display the Automatic Selection of Best Model dialog box. Use this dialog for access to the automatic (stepwise) selection method to choose the best model.

1 - p(1). STATISTICA first fits a model with no interactions, then with all two-way interactions, three-way interactions, etc., until a model that fits at the p-value greater than p(1) has been found. You can change this p-value via the 1 - p(1) box. Note that this first part is skipped if an initial User defined "starting model" is selected (see below).

2 - p(2). Next, STATISTICA eliminates from the initial model in a stepwise manner all effects that do not contribute significantly to the overall fit at the p(2) level of significance. The logic of the automatic selection algorithm is described in the Log-Linear Overview.

Starting model. The Starting model box contains two options: Automatic selection and User defined.

Automatic selection. If you select Automatic selection, STATISTICA will perform the computations as described above after clicking the OK button. During the backwards elimination stage of the automatic model selection procedure, STATISTICA will drop out each effect, one by one, and test its statistical significance.

User defined. If you select User defined, the Specify Model to be Tested dialog box is displayed after clicking the OK button. The model that you then specify will serve as the initial model from which non-significant effects [as specified by p(2)] will be eliminated. This option is also useful if you want to perform statistical significance tests for all effects in a previously determined model. If User defined is selected, the first step of the automatic selection procedure is skipped (see above).

OK. Click the OK button to display a summary of the Automatic Selection of Best Model if Automatic selection is selected as the Starting model, or to display the Specify Model to be Tested dialog box if User defined is selected as the Starting model.

Cancel. Click the Cancel button to return to the Log-Linear Analysis - Model Specification dialog box.