2007

Välkkynen, Pasi

In ubiquitous computing, the computing devices are embedded into the physical environment so that the users can interact with the devices at the same time as they interact with the physical environment. The various devices are connected to each other, and have various sizes and input and output capabilities depending on their purpose. These features of ubiquitous computing create a need for interaction methods that are radically different from the desktop computer interactions. Physical selection is an interaction task for ubiquitous computing and it is used to tell the user's mobile terminal which physical object the user wants to interact with. It is based on tags that identify physical objects or store a physical hyperlink to digital information related to the object the tag is attached to. The user selects the physical hyperlink by touching, pointing or scanning the tag with the mobile terminal that is equipped with an appropriate reader. Physical selection has been implemented with various technologies, such as radio-frequency tags and readers, infrared transceivers, and optically readable tags and mobile phone cameras. In this dissertation, physical selection is analysed as a user interaction task, and from the implementation viewpoint. Different selection methods - touching, pointing and scanning - are presented. Touching and pointing have been studied by implementing a prototype and conducting user experiments with it. The contributions of this dissertation include an analysis of physical selection in the ubiquitous computing context, suggestions for visualising the physical hyperlinks in both the physical environment and in the mobile terminal, and user requirements for physical selection as a part of an ambient intelligence architecture.