HandMark Menus: Rapid Command Selection and Large Command Sets on Multi-Touch Displays.

Command selection on large multi-touch surfaces can be difficult, because the large surface means that there are few landmarks to help users build up familiarity with controls. However, people's hands and fingers are landmarks that are always present when interacting with a touch display. To explore the use of hands as landmarks, we designed two hand-centric techniques for multi-touch displays -- one allowing 42 commands, and one allowing 160 -- and tested them in an empirical comparison against standard tab widgets. We found that the small version (HandMark-Fingers) was significantly faster at all stages of use, and that the large version (HandMark-Multi) was slower at the start but equivalent to tabs after people gained experience with the technique. There was no difference in error rates, and participants strongly preferred both of the HandMark menus over tabs. We demonstrate that people's intimate knowledge of their hands can be the basis for fast and feasible interaction techniques that can improve the performance and usability of interactive tables and other multi-touch systems.