Evolutionary induction of cost-sensitive decision trees

In the paper, a new method for cost-sensitive learning of decision trees is proposed. Our approach consists in extending the existing evolutionary algorithm (EA) for global induction of decision trees. In contrast to the classical top-down methods, our system searches for the whole tree at the moment. We propose a new fitness function which allows the algorithm to minimize expected cost of classification defined as a sum of misclassification cost and cost of the tests. The remaining components of EA i.e. the representation of solutions and the specialized genetic search operators are not changed. The proposed method is experimentally validated and preliminary results show that the global approach is able to effectively induce cost-sensitive decision trees.