Piles across space: Breaking the real-estate barrier on small-display devices

We describe an implementation that has users ‘flick’ notes, images, audio, and video files onto virtual, imaginary piles beyond the display of small-screen devices. Multiple sets of piles can be maintained in persistent workspaces. Two user studies yielded the following: Participants developed mental schemes to remember virtual pile locations, and they successfully reinstated pile locations after several days, while situated in varying environments. Alignment of visual cues on screen with surrounding physical cues in situ accelerated a sorting task when compared to other, non-aligned visual cues. The latter, however, yielded better long-term retention.