What is a terminal node in a decision tree?

• A. A node where decisions are made
• B. A starting node
• C. A random event
• D. A final outcome with no further consequences

Answer: (D)

In a decision tree, after following a path of tests, you arrive at a terminal node, also called a leaf. This node has no children, and it provides the final outcome of the decision process—a predicted class label in classification trees or a numeric value in regression trees. Because no further rules apply at this point, the path ends there, representing the final consequence of that sequence of decisions. The other descriptions describe parts of the tree that still perform decisions (internal nodes) or the starting point (the root), or ideas not inherent to the tree structure (random events). Thus, a terminal node is best understood as the final outcome with no further consequences.