Pseudoconservation of the Volume and Surface Area of a Solid Object

Abstract

PINARD, ADRIEN, and CHASS4, GILLES. Pseudoconservation of the Volume and Surface Area of a Solid Object. CmLD DEVELOPMENT, 1977, 48, 1559-1566. 4 equivalent groups of subjects, each group comprising 6 levels of schooling (first, second, third, sixth, and ninth grades and undergraduate students), were presented with 4 different tasks of surface-volume dissociation in order to see whether or not the conservation of 1 of these 2 properties (surface area or volume) of an object would wrongly induce a belief in the conservation of the other (pseudoconservation). Groups 1 and 2 were first shown that 3 differently shaped objects (boxes) were equal in surface areas (same amount of exterior paint): group 1 was then questioned on interior volume (same amount of cement?) and group 2 on exterior volume (same place in a jar of water?). The 2 other groups were first shown that the interior volumes (group 3) or exterior volumes (group 4) of 3 differently shaped objects were equal and then questioned on surface area. It was found that dissociating surface area from volume, as witnessed by elimination of pseudoconservation, (a) was not possible until the formal level of thinking, (b) was significantly easier in tasks involving transformation of surface area than in tasks involving transformation of volume, (c) was not more difficult in tasks involving interior volume than in tasks involving exterior volume. The results were discussed in terms of the differential rate of acquisition of the concepts of volume and area and of the factors involved in their coordination.