The Physical World as an Abstract Interface

We describe an approach to understanding the way in which people can use physical objects as if they were components of an abstract language. This arose from our study of common devices that cannot support direct manipulation, because users are controlling future operations such as VCR recording. We apply an adaptation of the Cognitive Dimensions of Notations framework, a vocabulary for the analysis and design of information devices, to the digitally augmented physical objects of tangible user interfaces. Our specific focus is on assisting collaboration, awareness and communication between individuals. We describe three case studies: rhetorical structure for children, shared information spaces within organizations, and assistive technology for individuals with dementia.