GeoGebra is dynamic mathematics software for all levels of education that joins arithmetic, geometry, algebra and calculus. On the one hand, GeoGebra is an interactive geometry system. You can do constructions with points, vectors, segments, lines, conic sections as well as functions and change them dynamically afterwards. On the other hand, equations and coordinates can be entered directly. Thus, GeoGebra has the ability to deal with variables for numbers, vectors and points, finds derivatives and integrals of functions and offers commands like Root or Extremum. These two views are characteristic of GeoGebra: an expression in the algebra view corresponds to an object in the graphics view and vice versa.
The EDRL research group works around a theoretical strain (embodied cognition), a methodological line (design-based research), and a disciplinary emphasis (mathematics). Thus, the laboratory hosts the full cycle of design-research projects that are geared to contribute to theory and practice of multi-modal mathematical learning and reasoning as well as to design theory.
K. Sedighian, and A. Sedighian. 18th Annual Meeting of the International Group for the Psychology of Mathematics Education -- the North American Chapter, Florida, USA, (1996)