Workspace Node: MARSplines - Specifications - Options Tab

In the MARSplines node dialog box, under the Specifications heading, select the Options tab to access options to specify the maximum complexity (number of basis functions) and stop-criterion for the iterative model building procedure implemented in MARSplines.

Element Name Description
Model specifications This group box contains the following options:
Maximum number of basis functions Specify the maximum number of basis functions to be added to the MARSplines model before pruning begins. Refer to the Introductory Overview and Technical Notes for more details.
Degree of interactions Specify the maximum degree of interactions between the independent (predictor) variables to be included in the model; for example, enter 1 to include main-effects only, enter 2 to consider all two-way interactions between predictors, etc.
Penalty Specify the value of the penalty for adding a basis function to the model. The penalty value is used in computations of the least-squares goodness-of-fit measure that guides the MARSplines algorithm; for details, see Technical Notes: The Multivariate Adaptive Regression Splines (MARSplines) Model.
Threshold This option prevents overfitting; the larger the threshold, the fewer basis functions will be added to the regression model.
Apply pruning Select this check box to apply pruning after fitting the requested number of basis functions to avoid overfitting, i.e. to limit model complexity. It is generally recommended to apply pruning in order to achieve a lower generalized cross validation error (i.e., predictive validity for new cases).
MD deletion Missing data can be deleted Casewise or substituted by means (Mean substitution) depending on the option selection in the MD deletion group box.
Casewise Select this option button to include only the cases that do not contain any missing data for any of the selected variables in the analysis.
Mean substitution Select this option button to replace missing data by the means for the respective variables (for this analysis only, not in the data file).

Options / C / W. See Common Options.

OK Click the OK button to accept all the specifications made in the dialog box and to close it. The analysis results will be placed in the Reporting Documents node after running (updating) the project.