Introduction

Cognitive development is the study of how fundamental processes of acquiring knowledge and information about the self and environment develop. The evaluation of cognitive development, known as cognitive assessment, is an important part of monitoring normal child development. The study of cognitive development, indeed the roots of cognitive assessment, can be traced to the French psychologist Jean Piaget (1896–1980). In many respects, Piaget's theories formed the basis for the modern study of cognitive development. Although not all of Piaget's tenets have withstood the test of time, they continue to influence modern cognitive assessment, if only conceptually (Wadsworth, 1996). Here we will briefly describe Piaget's theory of cognitive development as well his observations of the A-not-B tasks. Finally, we will illustrate the modern tools of cognitive ...