- Infer tree as well as possible.
- Convert tree to equivalent set of rules.
- Prune each rule by removing any preconditions that result in improving its estimated accuracy.
- Sort final rules by their estimated accuracy and consider them in this sequence when classifying.
- The tree on the left becomes the set of rules:
IF $(Outlook=Sunny) \wedge (Humidity=High)$ THEN $PlayTennis=No$ IF $(Outlook=Sunny) \wedge (Humidity=Normal)$ THEN $PlayTennis=Yes$ IF $(Outlook=Overcast)$ THEN $PlayTennis=No$ ...and so on