Tree-AS model nugget output

After you create a Tree-AS model, the following information is available in the Output viewer.

Model Information table

The Model Information table provides key information about the model. The table identifies some high-level model settings, such as:
  • The algorithm type used; either CHAID or Exhaustive CHAID.
  • The name of the target field selected in either the Type node or the Tree-AS node Fields tab.
  • The names of the fields selected as predictors in either the Type node or the Tree-AS node Fields tab.
  • The number of records in the data. If you build a model with a frequency weight, this value is the weighted, valid count which represents the records on which the tree is based.
  • The number of leaf nodes in the generated tree.
  • The number of levels in the tree; that is, the tree depth.

Predictor Importance

The Predictor Importance graph shows the importance of the top 10 inputs (predictors) in the model as a bar chart.

If there are more than 10 fields in the chart, you can change the selection of predictors that are included in the chart by using the slider beneath the chart. The indicator marks on the slider are a fixed width, and each mark on the slider represents 10 fields. You can move the indicator marks along the slider to display the next or previous 10 fields, ordered by predictor importance.

You can double-click the chart to open a separate dialog box in which you can edit the graph settings. For example, you can amend items such as the size of the graph, and the size and color of the fonts used. When you close this separate editing dialog box, the changes are applied to the chart that is displayed in the Output tab.

Top Decision Rules table

By default, this interactive table displays the statistics of the rules for the top five leaf nodes in the output, based on the percentage of total records that are contained within the leaf node.

You can double-click the table to open a separate dialog box in which you can edit the rule information that is shown in the table. The information that is displayed, and the options that are available in the dialog box, depend on the data type of the target; such as, categorical, or continuous.

The following rule information is shown in the table:
  • Rule ID
  • The details of how the rule is applied and made up
  • Record count for each rule. If you build a model with a frequency weight, this value is the weighted, valid count which represents the records on which the tree is based.
  • Record percentage for each rule
In addition, for a continuous target, an extra column in the table shows the Mean value for each rule.
You can alter the rule table layout using the following Table contents options:
  • Top decision rules The top five decision rules are sorted by the percentage of total records contained within the leaf nodes.
  • All rules The table contains all of the leaf nodes produced by the model but only shows 20 rules per page. When you select this layout, you can search for a rule by using the additional options of Find rule by ID and Page.

In addition, for a categorical target, you can alter the rule table layout using the Top rules by category option. The top five decision rules are sorted by the percentage of total records for a Target category that you select.

If you change the layout of the rules table, you can copy the modified rules table back to the Output viewer by clicking the Copy to Viewer button at the upper-left of the dialog box.