In this human behavior science fair project, the student will learn about Piaget's developmental stages and the Theory of Conservation. The student will investigate the age at which children understand the equality of numbers and mass....

The Piaget Society provides a short, easy-to-understand biography on Jean Piaget (1896-1980 CE), including a paragraph on his developmental theories.

This is an excellent resource on the life and work of the Swiss educational psychologist Jean Piaget (1896-1980).