Regression Trees and Pruning
Introduction
This demo version, after briefly presenting the regression trees, focuses on pruning. Pruning a regression tree (which consists in eliminating some well-chosen parts of the tree) is essential in order to get an optimal tree. Pruning therefore permits to avoid two potential issues:
- Reaching a too large tree leading to overfitting; that is obtaining a too complex model that fits the random noise included in the observations instead of the underlying pattern of these observations
- Having a too small tree leading to high bias
In order to optimize the predictive power of the model, the optimal balance between variance (high with a too large tree) and bias (high with a too small tree) has to be found. This is the final goal of the pruning technique.
Author: Julien Antunes Mendes | Publisher : Reacfin Academy