Decision Tree: What can I learn from the Box Tree?

The Box Tree displays nodes graphically showing the logical relationships between nodes (i.e. based on the rules), displaying as much of the variable/value text as possible.  The full details of that node can be seen in the Focus Panel, by hovering over a node and pressing shift.

The Node Id is displayed in the top left hand corner of each node.

  • The thickness of the border gives some indication of the size of the node.

Rule Information:

  • The Dimension used to split a node is written at the end of the line directly below the node.

  • The values of this dimension that define the rules for the two child nodes are written directly above the respective child node.

    For example, Node 1 is created by splitting Node 0 using the Income dimension, applying the rule "Income = Unknown £20-30k..."

Stopping Information:

  • A line is drawn across the box near the bottom to indicate that the node has been stopped by a node Stopping Condition during the build process.  (E.g. nodes 19, 20 have reached the Maximum Depth of 7).

  • A second line is drawn above this first line if a node is stopped manually by the user.  This may be in addition to the line indicating a Stopping Condition from the build process.

    This line will be dotted if it is being applied temporarily while growing the tree from a specific node.

  • When the tree stops growing, all leaf nodes are displayed with a black border, instead of a grey one.

For an explanation of the colours see What do all the colours mean?