The development of knowledge is never easy. One doesn't want to go over old ground again, but yet one needs to establish the new in the context of the old. One is also anxious about the novelty of the ideas are they new enough, or are they too 'way out' to be acceptable? In some fields perhaps these criteria are less important than in others. In education, I sense that 'novelty' is a tricky criterion, varying in value from society to society. In some societies the new ideas have to justify their adoption in the face to the old, tried and tested ideas. (Better the devil you know than the devil you don't!) In other societies the old ways have to justify their continuation in the face of the new, promising and exciting ideas. (I can't find a good proverb for this! Perhaps proverbs are all about preserving the past?) In any case, some people will argue, there is nothing new to be said about education anyway the problems are the same and it is only the context which changes. Mellin Olsen develops the reader's knowledge through this book in ways that are both novel and challenging. Their novelty is not in question, judging by reactions to them which vary from "they have nothing to do with mathematics education" to "they concern everything that is done in mathematics education".

The development of knowledge is never easy. One doesn't want to go over old ground again, but yet one needs to establish the new in the context of the old. One is also anxious about the novelty of the ideas are they new enough, or are they too 'way out' to be acceptable? In some fields perhaps these criteria are less important than in others. In education, I sense that 'novelty' is a tricky criterion, varying in value from society to society. In some societies the new ideas have to justify their adoption in the face to the old, tried and tested ideas. (Better the devil you know than the devil you don't!) In other societies the old ways have to justify their continuation in the face of the new, promising and exciting ideas. (I can't find a good proverb for this! Perhaps proverbs are all about preserving the past?) In any case, some people will argue, there is nothing new to be said about education anyway the problems are the same and it is only the context which changes. Mellin Olsen develops the reader's knowledge through this book in ways that are both novel and challenging. Their novelty is not in question, judging by reactions to them which vary from "they have nothing to do with mathematics education" to "they concern everything that is done in mathematics education".

In the first BACOMET volume different perspectives on issues concerning teacher education in mathematics were presented (B. Christiansen, A. G. Howson and M. Otte, Perspectives on Mathematics Education, Reidel, Dordrecht, 1986). Underlying all of them was the fundamental problem area of the relationships between mathematical knowledge and the teaching and learning processes. The subsequent project BACOMET 2, whose outcomes are presented in this book, continued this work, especially by focusing on the genesis of mathematical knowledge in the classroom. The book developed over the period 1985-9 through several meetings, much discussion and considerable writing and redrafting. Our major concern was to try to analyse what we considered to be the most significant aspects of the relationships in order to enable mathematics educators to be better able to handle the kinds of complex issues facing all mathematics educators as we approach the end of the twentieth century. With access to mathematics education widening all the time, with a multi tude of new materials and resources being available each year, with complex cultural and social interactions creating a fluctuating context of education, with all manner of technology becoming more and more significant, and with both informal education (through media of different kinds) and non formal education (courses of training etc. ) growing apace, the nature of formal mathematical education is increasingly needing analysis."

In the first BACOMET volume different perspectives on issues concerning teacher education in mathematics were presented (B. Christiansen, A. G. Howson and M. Otte, Perspectives on Mathematics Education, Reidel, Dordrecht, 1986). Underlying all of them was the fundamental problem area of the relationships between mathematical knowledge and the teaching and learning processes. The subsequent project BACOMET 2, whose outcomes are presented in this book, continued this work, especially by focusing on the genesis of mathematical knowledge in the classroom. The book developed over the period 1985-9 through several meetings, much discussion and considerable writing and redrafting. Our major concern was to try to analyse what we considered to be the most significant aspects of the relationships in order to enable mathematics educators to be better able to handle the kinds of complex issues facing all mathematics educators as we approach the end of the twentieth century. With access to mathematics education widening all the time, with a multi tude of new materials and resources being available each year, with complex cultural and social interactions creating a fluctuating context of education, with all manner of technology becoming more and more significant, and with both informal education (through media of different kinds) and non formal education (courses of training etc. ) growing apace, the nature of formal mathematical education is increasingly needing analysis."