Shumin does good work, now at google.
This paper reports an empirical investigation in which participants produced a set of stroke gestures with varying degrees of complexity and in different target sizes using both the finger and the pen. The recorded gestures were then analyzed according to multiple measures characterizing many aspects of stroke gestures. Our findings were as follows: (1) Finger drawn gestures were quite different to pen drawn gestures in basic measures including size ratio and average speed. Finger drawn gestures tended to be larger and faster than pen drawn gestures. They also differed in shape geometry as measured by, for example, aperture of closed gestures, corner shape distance and intersecting points deviation; (2) Pen drawn gestures and finger drawn gestures were similar in several measures including articulation time, indicative angle difference, axial symmetry and proportional shape distance; (3) There were interaction effects between gesture implement (finger vs.