An evaluation of coordination techniques for protecting objects and territories in tabletop groupware

Indirect input techniques allow users to quickly access all parts of tabletop workspaces without the need for physical access; however, indirect techniques restrict the available social cues that are seen on direct touch tables. This reduced awareness results in impoverished coordination; for example, the number of conflicts might increase since users are more likely to interact with objects that another person is planning to use. Conflicts may also arise because indirect techniques reduce territorial behavior, expanding the interaction space of each collaborator. In this paper, we introduce three new tabletop coordination techniques designed to reduce conflicts arising from indirect input, while still allowing users the flexibility of distant object control. Two techniques were designed to promote territoriality and to allow users to protect objects when they work near their personal areas, and the third technique lets users set their protection levels dynamically. We present the results of an evaluation, which shows that people prefer techniques that automatically provide protection for personal territories, and that these techniques also increase territorial behavior.