Group reaching over digital tabletops with digital arm embodiments

Abstract

In almost all collaborative tabletop tasks, groups require coordinated access to the shared objects on the table’s surface. The physical social norms of close-proximity interactions built up over years of interacting around other physical bodies cause people to avoid interfering with other people (e.g., avoiding grabbing the same object simultaneously). However, some digital tabletop situations require the use of indirect input (e.g., when using mice, and when supporting remote users). With indirect input, people are no longer physically embodied during their reaching gestures, so most systems provide digital embodiments – visual representations of each person – to provide feedback to both the person who is reaching and to the other group members. Tabletop arm embodiments have been shown to better support group interactions than simple visual designs, providing awareness of actions to the group. However, researchers and digital tabletop designers know little of how the design of digital arm embodiments affects the fundamental group tabletop interaction of reaching for objects. Therefore, in this thesis, we evaluate how people coordinate their interactions over digital tabletops when using different types of embodiments. Specifically, in a series of studies, we investigate how the visual design (what they look like) and interaction design (how they work) of digital arm embodiments affects a group’s coordinative behaviours in an open- ended parallel tabletop task. We evaluated visual factors of size, transparency, and realism (through pictures and videos of physical arms), as well as interaction factors of input and augmentations (feedback of interactions), in both a co-located and distributed environment. We found that the visual design had little effect on a group’s ability to coordinate access to shared tabletop items, that embodiment augmentations are useful to support group coordinative actions, and that there are large differences when the person is not physically co-present. Our results demonstrate an initial exploration into the design of digital arm embodiments, providing design guidelines for future researchers and designers to use when designing the next generation of shared digital spaces.