Kindergarten children and undergraduates were given a 2-category classification task to a learning criterion and then were given two probe trials to assess whether the categorization mode had been holistic or analytic. Both children and adults learned more easily the Similarity + Dimension (S+D) task which could be classified on the basis of overall similarity and a criterial dimension than the Similarity (S) task which could be classified on the basis of overall similarity only. In the S + D task both children and adults used the analytic mode more frequently than the holistic mode, whereas in the S task they used the holistic mode more frequently than the analytic mode. Discussion was made with reference to previous studies and a general developmental trend from holistic to analytic modes.