ABSTRACT
Developmental research has been troubled by a fundamental contradiction between theoretical assumptions and tools for analysis. On the one hand, theories of development such as Piaget’s (Piaget, 1957; Piaget, 1975) and the various neo-Piagetian theories (Case, 1985; Fischer, 1980; Halford, 1987; Siegler, 1981) posit intricate growth processes that predict complex patterns of development, such as stage discontinuities and equilibration. On the other hand, methodological tools for describing development have long limited analysis to a small set of simple growth patterns, mostly involving linear or monotonic change. Development is more complex and interesting than that! If the theories are at all correct, development should have diverse, complex shapes.
