7. Close the Results window.
Interactively Train a Decision Tree
To use the Decision Tree node to interactively train and prune a decision tree:
1. From the Model tab on the Toolbar, select the Decision Tree node icon. Drag the
node into the Diagram Workspace.
2. In the Diagram Workspace, right-click the Decision Tree node, and select Rename
from the resulting menu. Enter Interactive Decision Tree and then click
OK in the window that opens.
3. Connect the Control Point node to the Interactive Decision Tree node.
4. Select the Interactive Decision Tree node. In the Properties Panel, in the Train
properties group, click on the ellipses that represent the value of Interactive. The
Interactive Decision Tree window appears.
a. Select the root node (at this point, the only node in the tree), and then from the
Action menu, select Split Node. The Split Node window appears that lists the
candidate splitting rules ranked by logworth (-Log(p)). The
FREQUENCY_STATUS_97NK rule has the highest logworth. Ensure that this
row is selected, and click OK.
24 Chapter 5 • Build Decision Trees
b. The tree now has two additional nodes. Select the lower left node (where
FREQUENCY_STATUS_97NK is 3 or 4), and then from the Action menu,
select Split Node. In the Split Node window that opens, select
MONTHS_SINCE_LAST_GIFT, which ranks second in logworth, and click
Edit Rule to manually specify the split point for this rule. The Interval Split Rule
Enter 8 as the New split point, and click Add Branch. Then, select Branch 3
(>= 8.5) and click
Remove Branch. Click OK.
Interactively Train a Decision Tree 25
Ensure that MONTHS_SINCE_LAST_GIFT is selected in the Split Node
window, and click OK.
c. Select the first generation node that you have not yet split (where
FREQUENCY_STATUS_97NK is 1, 2, or Missing). From the Action menu,
select Split Node. In the Split Node window that opens, ensure that PEP_STAR
is selected, and click OK.
The tree now has seven nodes, four of which are leaf nodes. The nodes are
colored from light to dark, corresponding to low to high percentages of correctly
d. Select the lower right node (where FREQUENCY_STATUS_97NK is 1, 2, or
Missing and PEP_STAR is 0 or Missing). From the Action menu, select Train
Node. This selection causes SAS Enterprise Miner to continue adding
26 Chapter 5 • Build Decision Trees