Attribute blocks are described, with suggestions for developing sets of attribute materials. Various activities and games are described and illustrated. (MNS)

Advocates the use of classification activities in the elementary school curriculum as a means of developing thinking skills in children. Critical preclassification skills, classification activities (including simple and multiple classification), and classification tasks and materials are discussed. (Author/RH)

Examples are given of activities that begin with the classification of objects into sets and lead to concepts and activities in other branches of mathematics, in language arts, and in science. (DT)