Comparing Elicited Gestures to Designer-Created Gestures for Selection above a Multitouch Surface

Many new technologies are emerging that make it possible to extend interaction into the three-dimensional space directly above or in front of a multitouch surface. Such techniques allow people to control these devices by performing hand gestures in the air. In this paper, we present a method of extending interactions into the space above a multitouch surface using only a standard diffused surface illumination (DSI) device, without any additional sensors. Then we focus on interaction techniques for activating graphical widgets located in this above-surface space. We have conducted a study to elicit gestures for above-table widget activation. A follow-up study was conducted to evaluate and compare these gestures based on their performance. Our results showed that there was no clear agreement on what gestures should be used to select objects in mid-air, and that performance was better when using gestures that were chosen less frequently, but predicted to be better by the designers, as opposed to those most frequently suggested by participants.