2003 年 27 巻 2 号 p. 85-93
The purpose of this paper is to consider the idea of "figural concepts" (Fischbein 1993) and to verify the effect of this geometric construction activity in computer-based environments. Many Students have difficulties in learning geometry, because it deals with mental entities that possess simultaneously conceptual and figural characters (Fischbein 1993). Students tend to be influenced by figural characters in the process of geometrical activities. For problem situations in learning Geometry, Fischbein says that one has to do with a the third type of mental objects which simultaneously possess both conceptual and figural properties, that is "figural concepts", and we need to consider development of this matter in school mathematics. In this paper, it is supposed that the geometric construction activity in computer-based environments such as Cabri-Geometry is a means of developing "figural concepts", because this activity can interact between the conceptual and figural aspects of geometrical objects. The result of our study shows that the features of the software, such as degree of freedom of points in Cabri-Geometry, influence this activity. For developing "figural concepts", we need to study the design of computer-based learning environments for geometry to consider the factors in these environments.