Flick-and-brake: Finger control over inertial/sustained scroll motion

We present two variants of Flick-and-Brake, a technique that allows users to not only trigger motion by touch-screen flicking but also to subsequently modulate scrolling speed by varying pressure of a stationary finger. These techniques, which further exploit the metaphor of a massive wheel, provide the user with online friction control. We describe a finite-state machine that models a variety of flicking interaction styles, with or without pressure control. We report the results of a preliminary user study that shows that for medium to long distance scrolling the Flick-and-Brake techniques require less gestural activity than does standard flicking. One of the two variants of the technique is faster, but no less accurate, than state-of-the-art flicking. Users reported they preferred Flick-and-Brake over the standard flick and judged it more efficient. We indicate some pending issues raised by the results of this preliminary investigation.