Counting and Recounting Decision Trees

Counting (... and later, recounting) ensures that statistics are available for the various views.

Once a decision tree is counted initially, all subsequent recounts, in all views, must be performed manually.

Count a tree by changing the node view. Click the drop-down arrow beneath the Tree View button and choose Counts or Counts-labels.

Decision Tree Node View Menu

The node view options include:

• Standard: which displays the condition for each decision node, without counts. Each time you open a tree, the default node view is Standard which does not display counts.
• Counts: which displays the node condition and the total number of counts and weighted percentage of the total for each node.
• Counts-labels: which displays the decision node condition and the total number of counts and their weighted percentage of the total, together with their respective labels - i.e. #T and W%T.
• Click Profile View or Leaf View to view the statistics.

Note When you select Counts or Counts-labels, the Proportion and Recount buttons appear in the decision tree toolbar.

If you have not specified which profiling variables you are interested in, you will be prompted to do so when a tree count requires it - just select one or more variables presented from the drop-down list.

Important Xpress Insight only supports the profiling of non-categorical variables (i.e. numeric variables).

When you modify your tree - such as editing or inserting splits, merging rows etc, you will need to click Recount to update the count.

Displaying Split Proportions

The Proportion button appears in the decision tree toolbar when you are viewing the decision tree via Counts or Counts-labels. When clicked, the visible decision tree is color-coded to reflect the proportion of input records that pass into a node's split pathways.

Viewing Split Proportions

This kind of visualization can be very useful in quickly identifying splits that might benefit from additional tuning.