Decision Trees ================== Decision Tree from known features ----------------------------------- The idea of the decision tree is that you select a feature, split your data according to their label on this feature then recursively do that. Ways to split --------------- * Select feature based on its independent classification accuracy (at this point in the tree, so conditioned on the data it is given) * Select feature based on lowest entropy * How many possible trees are there with n features Pruning ---------- Remove leaves and assign label as majority of parent. Prepruning *********** Stop growing at some point (more popular) Postpruning ********************** Prune after tree made