TouchOver: decoupling positioning from selection on touch-based handheld devices

When compared to conventional desktop mouse input, touch input on handheld devices suffers from the lack of a main feature: that of a mouseover state that can provide users with dynamic pro-active information. In addition, with touch screens, selection precision is limited by undesired extra finger tracking during finger press and lift movements. We propose TouchOver, a multi-modal input technique for touch-screen accelerometers-enabled handheld devices where positioning is performed with a finger on the touch surface, while selection is triggered by a gentle "tilt forward" of the device. By doing so, TouchOver adds a mouseover-like state and improves selection precision while remaining compatible with existing interaction techniques such as Shift [10] devised to improve precision. Our formal user study shows a significant precision improvement over two other selection techniques as well as a good tradeoff between speed and accuracy.