ABSTRACT
Radical constructivism has provided a major theoretical foundation for current efforts to transform the teaching of mathematics (National Council of Teachers of Mathematics, 1989, 1991). It has contributed to change in the perspectives of mathematics educators concerning the nature of mathematical knowledge and activity and the nature of mathematics learning. As a result, traditional telland-show approaches to mathematics teaching are being rejected in favor of ways of teaching that are considered to be more optimal based on evolving views of mathematics and mathematics learning. However, the possibility for widespread and long-term change in the teaching of mathematics is dependent on a concomitant change in the education of both prospective and practicing mathematics teachers. This chapter focuses on the impact and potential impact of constructivism on mathematics teacher education and on mathematics teacher development research.
