This yearbook is the seventh for the Mathematics Education Research in Finland series and contains ten articles presented at the decennial jubilee colloquium. The first three articles discuss Constructivism both in general and with regard to mathematics education. Analysis is directed to the origins of constructivism, to the learning of mathematical concepts within systematic constructivism, and to assessment within a social constructivist framework. The fourth article analyzes the possibilities for deductive reasoning from the perspective of cognitive psychology, and the fifth discusses how to promote the mediation of thinking skills and heuristic processes of an expert in a complex technological environment. The next two articles discuss change both in the mathematics curriculum and in mathematics teaching. The sixth article describes the curriculum work in the Finnish comprehensive school during the last few years and the seventh article asks "Is school teaching changing?". The last three articles emphasize epistemological perspectives and historical sources in creating a new approach to the teaching of mathematics, give an outline of the history of mathematical contests in Estonia, and present an approach for predicting the level of difficulty of mathematical items. (MKR)