The uses of techlogy in education have kindled great interest in recent years. Currently, considerable resources are being expended to connect schools to the Internet, to purchase powerful (and increasingly affordable) computers, and on other implementations of educational techlogies. However, the mere availability of powerful, globally-connected computers is t sufficient to insure that students will learn--particularly in subjects that pose considerable conceptual difficulties, such as in science and mathematics. The true challenge is t just to put the newest techlogies in our schools, but to identify advanced ways to design and use these new techlogies to advance learning. This book offers a snapshot of current work that is attempting to address this challenge. It provides valuable and timely information to science and mathematics educators, educational and cognitive researchers, instructional techlogists and educational software developers, educational policymakers, and to scholars and students in these fields.