Mathematics as a discipline has a long history, emerging from many cultures, with a truly universal character. Mathematicians throughout the world have a fundamentally common understanding of the nature of mathematics and of its central problems and methods. Research mathematicians in any part of the world are part of a cohesive intellectual community that communicates fluently.

Mathematics education in contrast has a variable and culturally based character, and this is certainly true of educational organization and practice. Educational research is both an applied social science and a multidisciplinary domain of theoretical scholarship.

Among organizations devoted to mathematics education, The International Commission on Mathematical Instruction (ICMI) is distinctive because of its close ties to the mathematics community. The great challenges now facing mathematics education around the world demand a deeper and more sensitive involvement of disciplinary mathematicians than we now have, both in the work of educational improvements and in research on the nature of teaching and learning.

This book constitutes the Proceedings of the Ninth International Conference on Mathematical Education (ICME9), which was held in Tokyo/Makuhari Japan, in July and August 2000. ICME9 brought together experts from 70 countries, working to understand the challenges of mathematics education including boundary crossing and collaboration, such as the need to reconcile language, epistemology, norms of evidence and, in general, all of the intellectual and attitudinal challenges that face multidisciplinary research and development.