Quantitative and Qualitative Changes in the Development of Seriation.

This paper examines Piaget's account of the development of seriation. It reports a study that had two aims. One was to uncover some of the reasons why young children, who are not able to seriate when given the standard Piagetian task, often do show evidence of the ability to seriate when given a task that uses different materials. In particular, is there evidence for the Piagetian view that correct performance on the Piagetian task reflects operational abilities while correct performance on these others does not? The second aim was to begin to examine the mechanisms of transition that underlie the development of the child's increasing ability to seriate, i.e., to begin to describe the process by which various levels of seriation ability are achieved. Specifically, is the process the discontinuous one, de scribed by Piaget, that involves the acquisition of operational abilities that were not present earlier? These two aims must be assessed within the general Piagetian framework in which the most advanced seriation, that of Stage III, is based on operational abilities. These operational abilities consist of "relating each term [in the series] to the rest . . . [and of] . . . following a constant direction in this coordination" (Piaget, 1941/ 1965, p. 129). Following a constant direction enables children to seriate in a systematic way, from smallest to largest. Relating each term in the series to the rest (i.e., treating each element as being simultaneously smaller than some elements and larger than others) permits children to insert additional elements into the already-formed series and to correct the placement of additional elements that have been incorrectly inserted (Piaget, 1941/1965, pp. 129-131). In Stage II, instead of systematically choosing the smallest element, then the smallest of those remaining, etc., the child often chooses incorrectly from the to-be-seriated pile. That is, the child "constructs" the series