Children's ability to integrate class information

Coordination and integration of class information was examined using a multidimensional similarity judgment task in which four- and nine-year old children rated the similarity of pairs of stimuli sharing either one or two atribute values. Half the children at each age were assigned to an attention condition requiring they label relevant stimulus atributes before making their similarity ratings. The other children were in the nonattention condition, and rated similarity without labelling the attributes. The results indicated that four-year-olds in the attention condition and nine-year-olds in both conditions integrated class information in making their similarity judgments. Performance of the four-year-olds in the non-attention condition tended to improve across trials; they appeared to integrate class information on later trials.