| Bimanual interaction as applied to graphical computer user interfaces has been explored by researchers for over two decades. Despite these efforts, user interfaces utilizing continuous bimanual interaction have yet to make inroads into mainstream practice. While the technological obstacles to adoption are gradually disappearing, there remains another obstacle in that there remain many unanswered questions as to when and how to best utilize bimanual interaction techniques. This dissertation is an attempt at reducing this obstacle by identifying and addressing some of the open issues in bimanual interaction while also contributing new interaction techniques.; We develop, implement, and evaluate a bimanual interaction technique that allows users to control the view of a graphical scene with one hand and manipulate objects with the other. This technique removes the explicit multiplexing between navigation and manipulation that is present in unimanual interfaces, while improving perception of 3D scenes. Experiments show advantages in both performance time and subjective preference. Next, we present an experiment that shows that bimanual input performance and the reference principle of Guiard's Kinematic Chain model are both robust with respect to variations in kinesthetic reference frames as long as visual feedback is present. This implies that relative input devices can be used to perform bimanual interaction techniques without sacrificing performance. We then explore factors that govern performance in symmetric bimanual tasks—a class of tasks that has not been explored as extensively as the larger class of asymmetric tasks. Our results show that symmetric tasks are not always performed in a parallel and/or symmetric manner. A general asymmetry in the performance of symmetric tasks indicates that models of asymmetric interaction can be applied to symmetric tasks as well. Finally, inspired by a traditional technique used in the design industry, we develop and implement a bimanual interaction technique that allows for the creation of both curves and straight lines with a single tool. Our analysis of the properties of this technique indicates that strict adherence to all the principles of Guiard's Kinematic Chain model is not necessary for a bimanual interaction technique to be highly usable and successful. |
