The Interactive Tree Builder

You can generate a tree model automatically, where the algorithm decides the best split at each level, or you can use the interactive tree builder to take control, applying your business knowledge to refine or simplify the tree before saving the model nugget.

  1. Create a stream and add one of the decision tree nodes C&R Tree, CHAID, or QUEST.
    Note: Interactive tree building is not supported for either Tree-AS or C5.0 trees.
  2. Open the node and, on the Fields tab, select target and predictor fields and specify additional model options as needed. For specific instructions, see the documentation for each tree-building node.
  3. On the Objectives panel of the Build Options tab, select Launch interactive session.
  4. Click Run to launch the tree builder.

The current tree is displayed, starting with the root node. You can edit and prune the tree level-by-level and access gains, risks, and related information before generating one or more models.

Comments

  • With the C&R Tree, CHAID, and QUEST nodes, any ordinal fields used in the model must have numeric storage (not string). If necessary, the Reclassify node can be used to convert them.
  • Optionally, you can use a partition field to separate the data into training and test samples.
  • As an alternative to using the tree builder, you can also generate a model directly from the modeling node as with other IBM® SPSS® Modeler models. See the topic Building a Tree Model Directly for more information.