“…Past research in classification tasks has focused on how children learn (a) to form one class (Bruner & Olver, 1963;Inhelder & Piaget, 1959;Lovell, Mitchell, & Everett, 1962;Morf, 1959;Vigotsky, 1962), (b) to change their criteria for categorization (Heald & Marzolf, 1953;Lovell, Mitchell, & Everett, 1962), and (c) to compare the size and contents of different classes (Dodwell, 1962;Hyde, 1959;Inhedler & Piaget, 1959;Piaget, 1952).…”