Duval's Model of Visualization and Reasoning in Geometry
Operative Apprehension in Dynamic Geometry Environment (DGE)
[size=150][size=100][b]Operative apprehension[/b] in DGE: the insights revealed by operating on a pre-designed figure in the environment through [b]dragging[/b][/size][/size]
Information: Duval's Model of Visualization and Reasoning in Geometry