Multi-touch RST in 2D and 3D spaces: Studying the impact of directness on user performance

The RST multi-touch technique allows one to simultaneously control Rotations, Scaling, and Translations from multi-touch gestures. We conducted a user study to better understand the impact of directness on user performance for a RST docking task, for both 2D and 3D visualization conditions. This study showed that direct-touch shortens completion times, but indirect interaction improves efficiency and precision, and this is particularly true for 3D visualizations. The study also showed that users´ trajectories are comparable for all conditions (2D/3D and direct/indirect). This tends to show that indirect RST control may be valuable for interactive visualization of 3D content. To illustrate this finding, we present a demo application that allows novice users to arrange 3D objects on a 2D virtual plane in an easy and efficient way.