"Good enough" pointing in pervasive computing.

Opportunities are growing to engage in highly coordinated activities for multiple users with multiple screens. A great deal of research has explored how to support deictic reference in computer-mediated conversation, leading to what appears to be a general consensus among system builders in favor of a multi-mouse approach. While the multi-mouse provides an application-independent, context-free deictic reference solution, not only is it typically more costly to build, but also the usability of the tool regressively deteriorates as the number of users gets larger. Alternatives to the multi-mouse are application-specific, context-laden pointing mechanisms. Different research showed that the context-specific pointing conveys more information than a mere arrow. Yet, the context-free, multi-mouse pointing mechanism is generally taken as the panacean deixis solution in the groupware. Moreover, there have not been enough studies investigating tailorability or appropriatability of those different approaches. The needs for theories about when people profit from different kinds of support for pointing are current and large. We studied groups engaged in a highly coordinated, co-located task. We studied groups of three and used systems in which deictic reference could be achieved by a number of mechanisms. Our analysis shows that people chose pointing techniques that minimized the effort of communication; however, as the reference task became more complex, they employed more complex tools. Explicit support for pointing is desirable to support complex reference tasks, but not all pointing mechanisms match all cases. Different tools entail different deictic behaviors.