Interaction Spaces

As one moves further away from the WallBoard, the number of interactions available decreases. For example, contact-based pen interactions would be impossible from three meters away. The observation that certain interaction modalities are either impossible or lose their effectiveness at some distance from the WallBoard, leads to a classification of interaction spaces. Feasible interactions for each of the interaction spaces are shown in Table 1.

Table 1: Interactions in the three interaction spaces

We refer to these spaces based on a person's bodily relation to the WallBoard (Figure 2). In order to be able to touch the WallBoard, the user has to be within an arm's length of the WallBoard. Farther away, the user's gestures must be precise enough to be interpreted with respect to the WallBoard (spitting distance). Finally, within sight users are essentially observers, relying on vision and hearing, and any interaction with the WallBoard from this zone is through other computing devices. Since the interaction spaces are dependent on bodily relations, the spaces do not scale up with larger meeting rooms, such that for a regular meeting room, only the range of the Within-Sight Space may increase. A small office, on the other hand, may have just Arm's-Length space.

Figure 2: Interaction spaces on the WallBoard.

Arm's length

Within an arm's length of the WallBoard, users are right up close to the WallBoard, using all of the available interaction methods including gestures, tools, eye contact, voice, and computing devices. The principal and unique interactions in Arm's-Length Space are those involving gestures and tools. Here the metaphor of a whiteboard affords the use of tool-based interactions and is extended to include interactions through touch.

In the Arm's-Length Space, objects on the Wallboard may appear much larger than the user's physical size; therefore, touch-based interactions on the WallBoard may occur differently than those on desktop GISs. For example, positioning a building on a parcel through direct manipulation on a desktop GIS may utilize a snap-dragging technique (Bier 1989), however, such an operation becomes difficult to employ on the WallBoard, where the same building may appear to be two by three meters, and the parcel on which it is to be placed is even larger. Because users are so close to the large display, it becomes difficult for them to gain perspective. In the Arm's-Length Space, users may be required to move their head back and forth, change their position within the space, or even step away from the WallBoard in order to see the big picture. Therefore, when working in the Arm's-Length Space, users may frequently shift between spaces over the course of collaboration.

Benefits of interactions in Arm's-Length Space are attributed to the touch-sensitive screen and its size. Users can interact with representations of geographic objects that are closer to their actual size. Additionally, touch-based gestures allow users to manipulate objects directly, rather than through a pointing device.

Spitting distance

The second interaction space is within spitting distance of the WallBoard. This space is directly behind Arm's-Length Space, where gestures can still be detected and interpreted by the WallBoard's sensors. In Spitting-Distance Space, touch-based gestures and most tool-based interactions are no longer possible because users are too far away to reach the touch-sensitive screen. The principal interactions in this space are natural, empty-handed gestures, eye contact, and voice.

In Spitting-Distance Space, objects and scenes still may appear larger than the user, however, the entire WallBoard may be perceived easily by scanning with the eyes. Whereas desktop GISs require users to look into the scene, the large size of the WallBoard, provides users with the feeling that they are actually part of the scene. This consequence provides a more intuitive and natural interaction environment for natural, empty-handed gestures. Additionally, the WallBoard offers a benefit over other environments, such as virtual reality, in that multiple users can view and interact with the same space at the same time, while observing the others' manipulations.

Within sight

Beyond spitting distance, users are within sight of the WallBoard. In this space, displayed information can still be viewed, but because of the physical distance from the WallBoard, the size of objects may appear smaller than a user's hand. Even if gestures were detectable from this space, they would not be precise enough to be useful; therefore, interactions from this space only occur through other computing devices. A benefit of interacting in the Within-Sight Space is that user's can observe other collaborators and the WallBoard simultaneously.

Last updated on January 31, 1996.