Tree Display

You can control the initial appearance of the tree or completely suppress the tree display.

Tree. By default, the tree diagram is included in the output displayed in the Viewer. Deselect this option to exclude the tree diagram from the output.

Display. These options control the initial appearance of the tree diagram in the Viewer. All of these attributes can also be modified by editing the generated tree.

  • Orientation. The tree can be displayed top down with the root node at the top, left to right, or right to left.
  • Node contents. Nodes can display tables, charts, or both. For categorical dependent variables, tables display frequency counts and percentages, and the charts are bar charts. For scale dependent variables, tables display means, standard deviations, number of cases, and predicted values, and the charts are histograms.
  • Scale. By default, large trees are automatically scaled down in an attempt to fit the tree on the page. You can specify a custom scale percentage of up to 200%.
  • Independent variable statistics. For CHAID and Exhaustive CHAID, statistics include F value (for scale dependent variables) or chi-square value (for categorical dependent variables) as well as significance value and degrees of freedom. For CRT, the improvement value is shown. For QUEST, F, significance value, and degrees of freedom are shown for scale and ordinal independent variables; for nominal independent variables, chi-square, significance value, and degrees of freedom are shown.
  • Node definitions. Node definitions display the value(s) of the independent variable used at each node split.

Tree in table format. Summary information for each node in the tree, including parent node number, independent variable statistics, independent variable value(s) for the node, mean and standard deviation for scale dependent variables, or counts and percentages for categorical dependent variables.

To Control the Initial Tree Display

This feature requires the Decision Trees option.

  1. From the menus choose:

    Analyze > Classify > Tree...

  2. In the main Decision Tree dialog, click Output.
  3. Click the Tree tab.