Mid-Air Browsing and Selection in Image Collections

Abstract
Image collections are a common interaction pattern for 2D interfaces, however mid-air user interaction with collections has received little attention. We present a controlled experiment (within-groups, n=24) comparing three sets of hand gestures for mid-air browsing and selection in image collections, that were identified out of an elicitation study, using MS Kinect. Each set includes cursor-less gestures for browsing (sideways hand extension, wheel and swipe) and for selection/deselection (hand-up/hand-down). Task success was universal with high accuracy and few errors for all gestures. Sideways extension outperforms swipe and perceived effort for this gesture is significantly lower. Both gestures outperform wheel. We suggest that from a usability perspective, sideways hand extension should be preferred for browsing image galleries, if no other contextual factors apply. Also, the results of the elicitation study, in which most users proposed the swipe gesture for browsing, were not confirmed by the controlled usability experiment. This suggests a combined use of elicitation studies with rigorous usability testing, especially when gestures for particular user interface design patterns are sought.