

The XWeb architecture delivers interfaces to a wide variety of interactive platforms. XWeb's SUBSCRIBE mechanism allows multiple interactive clients to synchronize with each other. We define the concept of Join as the mechanism for acquiring access to a service's interface. Join also allows the formation of spontaneous collaborations with other people. We define the concept of Capture as the means for users to assemble suites of interactive resources to apply to a particular problem. These mechanisms allow users to access devices that they encounter in their environment rather than carrying all their devices with them. We describe two prototype implementations of Join and Capture. One uses a Java ring to carry a user's identification and to make connections. The other uses a set of cameras to watch where users are and what they touch. Lastly we present algorithms for resolving conflicts generated when independent interactive clients manipulate the same information.

This paper describes a new technique for transferring data between computers, the synchronized clipboard. Multiple computers can share a synchronized clipboard for all clipboard operations, so that data copied to the clipboard from one computer, using the standard Copy command, can be pasted directly on another computer using the standard Paste command. Synchronized clipboards are well-suited for a single user moving data among several computers in close proximity. We describe an implementation of synchronized clipboards that works across a wide range of existing systems, including 3Com PalmPilots, Microsoft Windows PCs, Unix workstations, and other Java-capable platforms. Our implementation adds no noticeable overhead to local copy and paste operations.

This paper describes a novel physical icon [3] (“phicon”) based system that can be programmed to issue a range of commands about what the user wishes to do with handdrawn whiteboard content. Through the phicon's UI, a command to process whiteboard context is issued using infrared signaling in combination with image processing and a ceiling-mounted camera system. We leverage camera systems that are already used for capturing whiteboard content [4] by further augmenting these systems to detect the presence and location of IR beacons within an image. An HDLC-based protocol and a built-in IR transmitter are used to send these signals.

In this paper, we describe our work on developing a system to support the personalization of a captured public experience. Specifically, we are interested in providing students with the ability to personalize the capture of the lecture experiences as part of the Classroom 2000 project. We discuss the issues and challenges involved in designing a system that performs live integration of personal streams of information with multiple other streams of information made available to it through an environment designed to capture public information.

Most current interface designs require that the user focus their attention on them in order to be of value. However, as the price of computation falls, and computational capabilities make their way into many everyday objects, the demand for attention from many different directions may begin to seriously reduce the usefulness of these computational objects. Ambient information displays are intended to fit in a part of the interface design space that does not have this property. They are designed to convey background or context information that the user may or may not wish to attend to at any given time. Ambient Displays are designed to work primarily in the periphery of a user's awareness, moving to the center of attention only when appropriate and desirable. This paper describes a new ambient information display that is designed to give a rich medium of expression placed within an aesthetically pleasing decorative object. This display --- the Information Percolator --- is formed by air bubbles rising up tubes of water. By properly controlling the release of air, a set of pixels which scroll up the display is created. This allows a rendition of any (small, black and white) image to be displayed. The detailed design and construction of this display device will be considered, along with several applications.

Intrabody communication (IBC) is a wireless communications technology that uses a person's body as the transmission medium for imperceptible electrical signals. Because communication is limited to the vicinity of a person's body, ambiguities arising from communication between personal devices and environmental devices when multiple people are present can, in theory, be solved simply. Intrabody communication also potentially allows data to be transferred when a person touches an IBC-enabled device. We have designed and constructed an intrabody communication system, modeled after Zimmerman's original design, and extended it to operate up to 38.4Kbps and to calculate signal strength. In this paper, we present quantitative measurements of data error rates and signal strength while varying hand distance to transceiver plate, electrode location on the body, touch plate size and shape, and several other factors. We find that plate size and shape have only minor effects, but that the distance to plate and the coupling mechanism significantly effect signal strength. We also find that portable devices, with poor ground coupling, suffer more significant signal attenuation. Our goal is to promote design guidelines for this technology and identify the best contexts for its effective deployment.

Many context-aware services make the assumption that the context they use is completely accurate. However, in reality, both sensed and interpreted context is often ambiguous. A challenge facing the development of realistic and deployable context-aware services, therefore, is the ability to handle ambiguous context. In this paper, we describe an architecture that supports the building of context-aware services that assume context is ambiguous and allows for mediation of ambiguity by mobile users in aware environments. We illustrate the use of our architecture and evaluate it through three example context-aware services, a word predictor system, an In/Out Board, and a reminder tool.

Impromptu is a mobile audio device which uses wireless Internet Protocol (IP) to access novel computer-mediated voice communication channels. These channels show the richness of IP-based communication as compared to conventional mobile telephony, adding audio processing and storage in the network, and flexible, user-centered call control protocols. These channels may be synchronous, asynchronous, or event-triggered, or even change modes as a function of other user activity. The demands of these modes plus the need to navigate with an entirely non-visual user interface are met with a number of audio-oriented user interaction techniques.

Users in ubiquitous computing environments need to be able to make serendipitous use of resources that they did not anticipate and of which they have no prior knowledge. The Speakeasy recombinant computing framework is designed to support such ad hoc use of resources on a network. In addition to other facilities, the framework provides an infrastructure through which device and service user interfaces can be made available to users on multiple platforms. The framework enables UIs to be provided for connections involving multiple entities, allows these UIs to be delivered asynchronously, and allows them to be injected by any party participating in a connection.

We describe the design of and experience with PointRight, a peer-to-peer pointer and keyboard redirection system that operates in multi-machine, multi-user environments. PointRight employs a geometric model for redirecting input across screens driven by multiple independent machines and operating systems. It was created for interactive workspaces that include large, shared displays and individual laptops, but is a general tool that supports many different configurations and modes of use. Although previous systems have provided for re-routing pointer and keyboard control, in this paper we present a more general and flexible system, along with an analysis of the types of re-binding that must be handled by any pointer redirection system This paper describes the system, the ways in which it has been used, and the lessons that have been learned from its use over the last two years.

This research explores distributed sensing techniques for mobile devices using synchronous gestures. These are patterns of activity, contributed by multiple users (or one user with multiple devices), which take on a new meaning when they occur together in time, or in a specific sequence in time. To explore this new area of inquiry, this work uses tablet computers augmented with touch sensors and two-axis linear accelerometers (tilt sensors). The devices are connected via an 802.11 wireless network and synchronize their time-stamped sensor data. This paper describes a few practical examples of interaction techniques using synchronous gestures such as dynamically tiling together displays by physically bumping them together, discusses implementation issues, and speculates on further possibilities for synchronous gestures.

Location-enhanced applications use the location of people, places, and things to augment or streamline interaction. Location-enhanced applications are just starting to emerge in several different domains, and many people believe that this type of application will experience tremendous growth in the near future. However, it currently requires a high level of technical expertise to build location-enhanced applications, making it hard to iterate on designs. To address this problem we introduce Topiary, a tool for rapidly prototyping location-enhanced applications. Topiary lets designers create a map that models the location of people, places, and things; use this active map to demonstrate scenarios depicting location contexts; use these scenarios in creating storyboards that describe interaction sequences; and then run these storyboards on mobile devices, with a wizard updating the location of people and things on a separate device. We performed an informal evaluation with seven researchers and interface designers and found that they reacted positively to the concept.

One of the problems with mobile media devices is that they may distract users during critical everyday tasks, such as navigating the streets of a busy city. We addressed this issue in the design of eyeLook: a platform for attention sensitive mobile computing. eyeLook appliances use embedded low cost eyeCONTACT sensors (ECS) to detect when the user looks at the display. We discuss two eyeLook applications, seeTV and seeTXT, that facilitate courteous media consumption in mobile contexts by using the ECS to respond to user attention. seeTV is an attentive mobile video player that automatically pauses content when the user is not looking. seeTXT is an attentive speed reading application that flashes words on the display, advancing text only when the user is looking. By making mobile media devices sensitive to actual user attention, eyeLook allows applications to gracefully transition users between consuming media, and managing life.

In this paper, we present a methodology for recognizing seatedpostures using data from pressure sensors installed on a chair.Information about seated postures could be used to help avoidadverse effects of sitting for long periods of time or to predictseated activities for a human-computer interface. Our system designdisplays accurate near-real-time classification performance on datafrom subjects on which the posture recognition system was nottrained by using a set of carefully designed, subject-invariantsignal features. By using a near-optimal sensor placement strategy,we keep the number of required sensors low thereby reducing costand computational complexity. We evaluated the performance of ourtechnology using a series of empirical methods including (1)cross-validation (classification accuracy of 87% for ten posturesusing data from 31 sensors), and (2) a physical deployment of oursystem (78% classification accuracy using data from 19sensors).