Finger-Count & Radial-Stroke Shortcuts: Two Techniques for Augmenting Linear Menus on Multi-Touch Surfaces

• Bailly Gilles
• Lecolinet Eric
• Guiard Yves

• Menu techniques
• Multi-touch
• Multi-finger interaction
• Two-handed interaction

Figure 1: Left: Finger-Count Shortcuts: the non-dominant hand (NDH) selects the pulldown menu in the menubar while the dominant hand (DH) selects the item. Favorite Menus (resp. items) are selected according to the number of fingers of the NDH (resp. DH) that are pressed on the surface. Right: Radial-Stroke Shortcuts: at least two fingers of the NDH are pressed to activate the menubar mode while one finger of the DH performs a multi-stroke radial gesture. ABSTRACT We propose Radial-Stroke and Finger-Count Shortcuts, two techniques aimed at augmenting the menubar on multi-touch surfaces. We designed these multi-finger two-handed interaction techniques in an attempt to overcome the limitations of direct pointing on interactive surfaces, while maintaining compatibility with traditional interaction techniques. While Radial-Stroke Shortcuts exploit the well-known advantages of Radial Strokes, Finger-Count Shortcuts exploit multi-touch by simply counting the number of fingers of each hand in contact with the surface. We report the results of an experimental evaluation of our technique, focusing on expert-mode performance. Finger-Count Shortcuts outperformed Radial-Stroke Shortcuts in terms of both easiness of learning and performance speed.