What is the target?

Reconciling the differential perspective with the Piagetian perspective is a very difficult task. The Piagetian perspective admits the existence of in terindividual differences but interprets them as noise masking the universa l logical succession of structures, whereas the differential perspective vi ews development as consisting of "vicarious processes." As a matter of hist orical fact, the main aim of the "procedural studies" carried out in Geneva was to introduce concrete microgenesis into the macrogenetic Piagetian mod el.