Machine Learning, Decision Tree, Explainable Ai, Beginners Guide, Understanding.
iris, so the group is very homogeneous and Gini impurity is a measure of homogeneity. The Gini impurity for the right leaf is : We find the same result as the one shown in the tree graph. Moreover this Gini impurity is close to 0.5 because there are almost as much virginica as versicolor irises.