ABSTRACT
In Chapter 1 we described a set of criteria by which scientific theories may be judged. In respect of some of these criteria Piaget's theory is enormously successful. It is parsimonious and wide ranging. With a few central concepts almost the whole range of human cognitive experience is encompassed. The development of specific concepts such as space and time is handled in the same terms as broader issues such as the child's understanding of geometry and ultimately, the child's conception of the world. The theory has raised fascinating questions and continues to do so. The vast flow of Piagetian literature shows no sign of ebbing.
