Three design principles learned through developing a series of 3D sketch systems: "Memory Capacity", "Cognitive Mode", and "Life-size and Operability"

We have been studying the creativity-centered media to ensure that systems truly support creative and intelligent human activities. However, it has gradually become obvious that current advanced support systems have a serious drawback: instead of promoting creative work, they often discourage creativity or let us stop thinking. In this paper, we focus on the 3D sketch system that supports the design of 3D objects by drawing them in the 3D space directly, because they are not used by designers in real fields but are just treated as a mere attraction in an amusement park. We propose three design principles, "Memory Capacity", "Cognitive Mode", and "Life-size and Operability", which make the 3D sketch system truly useful for the designer. They have been gradually derived in the accordance with our cognitive experiment and developing series of 3D sketch system.