Navigating Large Decision Trees

To preserve the transparency of Decision Trees, it is generally recommended that the size of the tree should not exceed what can easily be browsed (e.g. no more than a couple of screen pages to scroll). However there are instances where this is not feasible, for example when Decision Trees are induced from Cases.

In this situation it may be helpful to collapse parts of the Decision Tree, thereby allowing the developer to focus on the part of the tree logic under investigation at any given time. Three options are provided for this purpose (accessible from the context menu after a right mouse click):

Collapse Sub-Tree / Expand Sub-Tree (F7).
Collapse Sub-Tree is shown if the Sub-Tree is expanded. This will collapse all the nodes below this node and display the symbol
Expand Sub-Tree is shown if the Sub-Tree is already collapsed. This will expand the Sub-Tree by one level. (this can also be done using the keyboard key)
Expand Full Sub-Tree. This option will expand all the nodes in the Sub-Tree to the Leaf nodes.
Collapse to Path. This option will collapse all the Sub-Trees except a single Path leading from the root node of the tree to highlighted node.

See also the "Auto Collapse Large Trees" User Option

Another way to help with navigating a large Decision Tree is by using the Show/Hide Tree Navigator to display an alternative view of the Decision Tree,