1. A method for using a continuous attribute as an input attribute for a decision tree for a given output attribute, where a score can be calculated which corresponds to a measure of the usefulness of a subrange of an input attribute considered as a state over said given output attribute, comprising: determining a range of values for said continuous attribute; dividing said range into partitions, where each partition corresponds to a sub-range of said range; and determining whether to merge said at least two adjacent partitions.