Great work! In this lesson, you learned how to create decision trees and use them to make classifications. Here are some of the major takeaways:

• Good decision trees have pure leaves. A leaf is pure if all of the data points in that class have the same label.
• Decision trees are created using a greedy algorithm that prioritizes finding the feature that results in the largest information gain when splitting the data using that feature.
• Creating an optimal decision tree is difficult. The greedy algorithm doesn’t always find the globally optimal tree.
• Decision trees often suffer from overfitting. Making the tree small by pruning helps to generalize the tree so it is more accurate on data in the real world.