A decision tree is a tree-like graph, a sequential diagram illustrating all of the possible decision alternatives and the corresponding outcomes. Starting from the root of a tree, every internal node represents the basis on which a decision is made; each branch of a node represents how a choice may lead to the next nodes; and finally, each terminal node, the leaf, represents the outcome produced.
For example, we have just made a couple of decisions that brought us to the point of using a decision tree to solve our advertising problem:
The first condition, or the root is whether the feature type is ...
