Three approaches to assessing the conservation of weight concept

Identity versus equivalence in weight conservation

“…The results of the present study are basically consistent with Piaget's outlook about equivalence and identity and are in agreement with the findings of Northman and Gruen [3] and Stone [4]. As stated earlier, the performance of the children in the equivalence test did not differ significantly from their performance in the identity test for each of grades 1-5.…”

“…Their results supported Piaget's view that the two forms of conservation emerge together. The latter finding is supported by the results of another study by Stone [4] involving 252 subjects from an elementary school in Iowa. Stone found no significant difference between the levels of performance reflected from the equivalence and identity weight conservation tests at any of the age levels tested.…”