We report on the development of a "language of description" that facilitates an integrated analysis of classroom video data in terms of the quality of the teaching-learning process and the students' access to valued forms of mathematical knowledge. Our research setting is the introduction of software for teachers for improving the mathematical…

Our main goal in this study is to exemplify that a meticulous design can lead pre-service teachers to engage in productive unguided peer argumentation. By productivity, we mean here a shift from reasoning based on intuitions to reasoning moved by logical necessity. As a subsidiary goal, we aimed at identifying the kinds of reasoning processes…

The LOGO subroutine turtle geometry and Euclidean geometry are compared with respect to their treatment of similarity and difference of plane figures. The problem and its proposed solution of introducing a FLIP operation are viewed briefly from the perspectives of mathematics, computer science, and education. (MDH)

Described are problems of the teacher's management of computer use during the learning process and student acquisition of new knowledge that can be transferred to situations outside the software environment. Choices made to address these problems are illustrated as students learn axial symmetry using the microworld Cabri-gomtre. (MDH)