Matching interface design with user tasks. Modalities of interaction with CMU wearable computers

To maximize the effectiveness of wearable systems in mobile computing environments, interface design must be carefully matched with user tasks. By constructing mental models of user actions, interface elements may be chosen and tuned to meet the specific software and hardware requirements of specific procedures. This article details specific cases of task study and interface implementation by the Carnegie Mellon University (CMU) wearable computer project over six generations of systems. An abstract model for application interface design is given, with examples of implementation on both embedded systems and general purpose platforms. It describes the factors of human interface in wearable systems design focusing on how the application impacts the design and especially the user interface. First examined is the process of modeling specific user tasks, and establishing a linkage with the system interface that closely mirrors this model. Next is an overview of the VuMan embedded systems, followed by a description of the Navigator general-purpose machines. The article concludes with a summary of information developed through the design and testing of these wearable systems.