Why do trees benefit from pruning?
Classification trees can grow indefinitely, until they are told to stop or run out of data to divide-and-conquer.
Just like trees in nature, classification trees that grow overly large can require pruning to reduce the excess growth. However, this generally results in a tree that classifies fewer training examples correctly.
Why, then, are pre-pruning and post-pruning almost always used?
This exercise is part of the course
Supervised Learning in R: Classification
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