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 di-rectly above or in front of a multitouch surface. Such tech-niques 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 fo-cus on interaction techniques for activating graphical widg-ets 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 perfor-mance 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. Author Keywords Multimodal interaction; natural human computer interac