Touchpad and touchscreen interaction using multiple fingers is emerging as a valuable form of high-degree-of-freedom input. While bimanual interaction has been extensively studied, touchpad interaction using multiple fingers of the same hand is not yet well understood. We describe two experiments on user perception and control of multi-touch interaction using one and two hands. The first experiment addresses how to maintain perceptual-motor compatibility in multi-touch interaction, while the second measures the separability of control of degrees-of- freedom in the hands and fingers. Results indicate that two-touch interaction using two hands is compatible with control of two points, while twotouch interaction using one hand is compatible with control of a position, orientation, and hand-span. A slight advantage is found for two hands in separating the control of two positions. Author Keywords Multi-touch input, bimanual interaction, high-degree-offreedom input, interaction design. ACM...
Tomer Moscovich, John F. Hughes