Task differences on conservation and transitivity problems

Task differences were assessed with 120 first graders in a 2 × 3 × 3 factorial design combining Socioeconomic level (middle vs lower), Concepts (conservation of length, transitivity of length, and conservation of continuous quantity), and Tasks (three tasks for each concept selected on the basis of frequency of usage). As predicted, task by concept interactions were found on all four task response measures. This finding is consistent with Piaget's concept of horizontal decalage and with Flavell and Wohlwill's competence-performance model, which proposes that intermediate phases of stage transition are characterized by considerable intertask differences and initial and final phases by intertask consistency in performance. The importance of investigating the effects of task variables on multiple dependent measures at various age levels and points in time was emphasized. Concept, task, and socioeconomic class differences were also found on some of the measures.