Many of the contributors to this book, as well as much of the mathematics education research community in general, take a psychological orientation toward learning, following the construc tivist theoretical tenets of Piaget. They take an individual and developmental perspective when looking at children's learning, in some cases integrating concepts from cognitive science and information processing theory. One reason for the reliance on Piaget's theory is that it builds from notions that are fundamental to mathematics (e.g., the role of logic and logical reasoning). It also offers a mechanism to account for conceptual change, in the ideas of assimilation and accommodation. However, this is a perspective that focuses exclusively on the individual and on the mental processes of learning within the individual. Several contributors to this book see teaching as playing a fundamental role in creating conditions that enable children to make changes in their thinking that are necessary
to understand die ideas and concepts that form the logic of mathematics.