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Decision Tree¶

Estimated time to read: 1 minute

A DT makes predictions by breaking down a problem into a series of yes/no questions, orgranized like a flowchart. It's called a "tree" because it starts at a root and branches out into nodes (decisions) and leaves (final predictions),

Terminologies¶

leaf node¶

A node that doesn't have any child nodes.

splitting¶

The process of dividing a node into two or more sub nodes

pruning¶

The opposite of splitting, that removes subnodes of a decision node.

Decision Tree vs If-Else¶

It is a series of if-else statements. The key is building these rules automatically, it is not really about the tree once built, it is about how we created it. DT is not exactly in a brute-force, try-everything way. It uses a greedy algorithm to pick the best split at each step.