Glossary · Phase 3 · Machine learning
Pruning
Cutting back the branches of a decision tree that don't help on validation data, so it overfits less.
Try it now
Raise the depth and watch the score on seen points climb to 100% while the score on new points stops improving.
Learn it properly
Decision trees · Learn a flowchart of yes/no questions. About 30 minutes.
Other terms from the same lesson
- decision tree: A model that asks a series of yes/no questions about the inputs to reach a prediction.
- Gini impurity: How mixed a group is: the chance two random picks from it (with replacement) disagree. 0 means everyone in the group has the same label.
- leaf: An end point of a decision tree, with no more questions. It gives the prediction.
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