Studies and guidelines for two concurrent stroke gestures

This paper investigates thumb-index interaction on touch input devices, and more precisely the potential of two concurrent stroke gestures , i.e . in which fingers same hand concurrently draw one each. We present fundamental studies, using such for two-dimensional control, by drawing figures, other command activation, roughly sketching figures. Results give a first analysis user performance 35 with varying complexity based numbers turns symmetries. All gestures, were grouped into six families. From these results we classify families propose new guidelines designing future mobile interfaces. For instance, favouring anchored (forefinger while thumb remains still surface) to increase bandwidth when forefinger precision is required. • One empirical study evaluating 30 categorised 5 A second recognition set. detailed helped deriving sets usable modes.