Abstract
In many cases, the CAD education is provided in such a way that students are given exercises in which they have to draft graphics using CAD commands. Students keep in mind an image of the hand−drafting procedures and concepts while using CAD. Many of students, have an insufficient understanding of drafting with CAD despite the fact they have no problem in understanding hand-drafting. My research focused on the physical movements performed during these operations. I conducted an experiment using puzzles in order to identify the characteristics of the operational procedures from the differences arising from direct and indirect operations. In conclusion, When the subjects perform a graphic operation directly, they start to think that they should try to assemble the pieces to find the appropriate shape so as to complete the task. When subjects perform a graphic operation indirectly, they start to think that they should first envision the graphic to be produced by the operation and then start to perform the operation based on what they have envisioned.
