Individuals with cognitive impairments would prefer to live independently, however issues in wayfinding prevent many from fully living, working, and participating in their community. Our research has focused on designing, prototyping, and evaluating a mobile wayfinding system to aid such individuals. Building on the feedback gathered from potential users, we have implemented the system’s automated direction selection functionality. Using a decision-theoretic approach, we believe we can create better wayfinding experience that assists users to reach their destination more intuitively than traditional navigation systems. This paper describes the system and results from a study using systemgenerated directions that inform us of key customization factors that would provide improved wayfinding assistance for individual users.

Mobile phones are an attractive platform for landmark-based pedestrian navigation systems. To be practical, such a system must be able to automatically generate lightweight directions that can be displayed on these mobile devices. We present a system that leverages an online collection of geotagged photographs to automatically generate navigational instructions. These are presented to the user as a sequence of images of landmarks augmented with directional instructions. Both the landmark selection and image augmentation are done automatically. We present a user study that indicates these generated directions are beneficial to users and suggest areas for future improvement.

It is difficult to design and test location-enhancedapplications. A large part of this difficulty is due to the added complexity of supporting location. Wizard of Oz (WOz) has become an effective technique for the early stage design of location-enhanced applications because it allows designers to test an application prototype bysimulating nonexistent components such as location sensing. However, existing WOz tools 1) require nontrivial effort from designers to specify how a prototype should behave before it can be tested with end users, and 2)support only limited control over application behavior during a test. BrickRoad is a WOz tool for spontaneousdesign of location-enhanced applications. It lowers the threshold to acquiring user feedback and exploring a design space. With BrickRoad, a designer does not need to specify any interaction logic and can experiment on-the-fly with different designs during testing. BrickRoad is a valuable complement to existing tool support for the early stage design of location-enhanced applications.

Assistive technology for wayfinding will significantly improve the quality of life for many individuals with cognitive impairments. The user interface of such a system is as crucial as the underlying implementation and localization technology. We built a system using the Wizard-of-Oz technique that let us experiment with many guidance strategies and interface modalities. Through user studies, we evaluated various configurations of the user interface for accuracy of route completion, time to completion, and user preferences. We used a counter-balanced design that included different modalities (images, audio, and text) and different routes. We found that although users were able to use all types of modalities to find their way indoors, they varied significantly in their preferred modalities. We also found that timing of directions requires careful attention, as does providing users with confirmation messages at appropriate times. Our findings suggest that the ability to adapt indoor wayfinding devices for specific users' preferences and needs will be particularly important.

In this paper, we propose a system that uses the wireless networking and microphone interfaces of mobile devices to determine location to room-level accuracy. The wireless network provides a synchronizing pulse along with information about the room. This is accompanied by an ultrasound beacon that allows us to resolve locations to the confines of a physical room (since audio is mostly bounded by walls). We generate the wireless data and ultrasound pulses from the existing PCs in each room; a PDA carried by a user listens for both signals. Thus, our approach does not require special hardware. We do not use ultrasound to send data. As a result we dramatically reduce the computational burden on the mobile device while also decreasing the latency of location resolution. Our results indicate that (i) ultrasound detection is robust even in noisy environments with many reflective surfaces; and (ii) that we can determine the correct room within a couple of seconds with high probability even when the ultrasound emitting PCs are not synchronized.

Design patterns are a format for capturing and sharing design knowledge. In this paper, we look at a new domain for design patterns, namely ubiquitous computing. The overall goal of this work is to aid practice by speeding up the diffusion of new interaction techniques and evaluation results from researchers, presenting the information in a form more usable to practicing designers. Towards this end, we have developed an initial and emerging pattern language for ubiquitous computing, consisting of 45 pre-patterns describing application genres, physical-virtual spaces, interaction and systems techniques for managing privacy, and techniques for fluid interactions. We evaluated the effectiveness of our pre-patterns with 16 pairs of designers in helping them design location-enhanced applications. We observed that our pre-patterns helped new and experienced designers unfamiliar with ubiquitous computing in generating and communicating ideas, and in avoiding design problems early in the design process.