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."

Es besteht heute weitgehend Obereinstimmung darin, daB fUr die weitere Entwicklung der Mathematikdidaktik lehrbuchartige Darstellungen umfassender Teilbereiche, vor all em Dar- stellungen der Didaktik einzelner Schulstufen, besonders wichtig sind. FUr den dadurch erhofften ProzeB der Systematisierung und der Integration, der gegenseitigen Anregung und Erganzung, der Kritik und der Herausarbeitung offener Fragen wird es zweifellos be- lebend sein, wenn Darstellungen miteinander konfrontiert werden k6nnen, die aus ver- schiedenen Richtungen kommen und dementsprechend verschiedene Akzente setzen. Ich begrUBe es aus den genannten GrUnden, daB der Verlag Vieweg in sein Programm "Didaktik der Mathematik" auch die vorliegende Obersetzung eines Lehrbuches aufge- nommen hat, das in den Niederlanden 1973 erschienen ist und dort mittlerweile als Stan- dardwerk gilt. Der Autor, Johan van Dormolen, ist ein Didaktiker, der Uber die Grenzen seines Landes hinaus anerkannt ist und durch seinen Vortrag anlaBlich der Bundestagung Augsburg 1976 einem breiteren deutschen Publikum bekannt geworden ist. Herr van Dormolen verfUgt Uber eine langjahrige Berufserfahrung als Gymnasiallehrer und ist seit mehreren J ahren als Dozent an der Universitat Utrecht mit der fachdidaktischen Ausbildung von Studenten befaBt. 1m vorliegenden Such ist ihm m.E. eine gelungene Synthese seiner reichen praktischen Lehrerfahrungen mit Konzepten der Unterrichtspsychologie (de Cecco, Skemp, van Hiele) gelungen und es ist zu wUnschen, daB das Buch die weitere fachdidaktische Diskussion in Deutschland befruchten wird.