Missing Values with CRT

Now let's try the same basic analysis, except we'll use CRT as the growing method.

  1. In the main Decision Tree dialog box, for the growing method, select CRT.
  2. Click Criteria.
  3. Make sure that the minimum number of cases is still set at 400 for parent nodes and 200 for child nodes.
  4. Click the Surrogates tab.

    Note: You will not see the Surrogates tab unless you have selected CRT or QUEST as the growing method.

    Figure 1. Criteria dialog box, Surrogates tab
    Criteria dialog box, Surrogates tab

    For each independent variable node split, the Automatic setting will consider every other independent variable specified for the model as a possible surrogate. Since there aren't very many independent variables in this example, the Automatic setting is fine.

  5. Click Continue.
  6. In the main Decision Tree dialog box, click Output.
    Figure 2. Output dialog box, Statistics tab
    Output dialog box, Statistics tab
  7. Click the Statistics tab.
  8. Select Surrogates by split.
  9. Click Continue, and then click OK to run the procedure.

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