Developing 3D dynamic geometry software: theoretical perspectives on design

摘要

This paper reports on the theoretical perspectives underpinning the design of a 3D geometry software environment called 3DMath. The idea of 3DMath is to develop a dynamic three dimensional geometry microworld, which enables (i) students to construct, observe and manipulate geometrical figures in 3D space, (ii) students to focus on modeling geometric situations, and (iii) teachers to help students construct their understanding of stereometry. During the developmental of 3DMath, the key elements of visualization (mental images, external representations, and the processes and abilities of visualization) are being carefully taken into consideration. The aim of this paper is to illustrate how the design of the 3DMath software is informed by these key elements of visualization, as well as by theories related to the philosophical basis of mathematical knowledge and to semiotics. Thus, the paper describes how the features of the software are designed to enhance the elements of visualization, and to satisfy the characteristics of instructional techniques that are appropriate to these theoretical perspectives.