spatial

Screen-less wearable devices allow for the smallest form factor and thus the maximum mobility. However, current screen-less devices only support buttons and gestures. Pointing is not supported because users have nothing to point at. However, we challenge the notion that spatial interaction requires a screen and propose a method for bringing spatial interaction to screen-less devices.

We present Imaginary Interfaces, screen-less devices that allow users to perform spatial interaction with empty hands and without visual feedback. Unlike projection-based solutions, such as Sixth Sense, all visual "feedback" takes place in the user's imagination. Users define the origin of an imaginary space by forming an L-shaped coordinate cross with their non-dominant hand. Users then point and draw with their dominant hand in the resulting space.

With three user studies we investigate the question: To what extent can users interact spatially with a user interface that exists only in their imagination? Participants created simple drawings, annotated existing drawings, and pointed at locations described in imaginary space. Our findings suggest that users' visual short-term memory can, in part, replace the feedback conventionally displayed on a screen.

Spatial layout is frequently used for managing loosely organized information, such as desktop icons and digital ink. To help users organize this type of information efficiently, we propose an interface for manipulating spatial aggregations of objects. The aggregated objects are automatically recognized as a group, and the group structure is visualized as a two-dimensional bubble surface that surrounds the objects. Users can drag, copy, or delete a group by operating on the bubble. Furthermore, to help pick out individual objects in a dense aggregation, the system spreads the objects to avoid overlapping when requested. This paper describes the design of this interface and its implementation. We tested our technique in icon grouping and ink relocation tasks and observed improvements in user performance.

Triggering shortcuts or actions on a mobile device often requires a long sequence of key presses. Because the functions of buttons are highly dependent on the current application's context, users are required to look at the display during interaction, even in many mobile situations when eyes-free interactions may be preferable. We present Virtual Shelves, a technique to trigger programmable shortcuts that leverages the user's spatial awareness and kinesthetic memory. With Virtual Shelves, the user triggers shortcuts by orienting a spatially-aware mobile device within the circular hemisphere in front of her. This space is segmented into definable and selectable regions along the phi and theta planes. We show that users can accurately point to 7 regions on the theta and 4 regions on the phi plane using only their kinesthetic memory. Building upon these results, we then evaluate a proof-of-concept prototype of the Virtual Shelves using a Nokia N93. The results show that Virtual Shelves is faster than the N93's native interface for common mobile phone tasks.