In this paper, we explore the opportunity of bringing unistroke text entry to freehand gesture interfaces. Using existing text entry methods directly in such interfaces is impractical because of the differences between freehand gestures and traditional forms of input. To address this problem, we consider the design constraints of text entry methods using freehand gestures, and present AirStroke, a new technique based on a reengineering of the well-known unistroke technique Graffiti. Using Graffiti's alphabet, AirStroke takes advantage of the richer input capabilities of two-handed freehand gestures by providing combined mode selection and character entry with one hand, as well as word completion with the other hand. A longitudinal study suggests that AirStroke has competitive speed and accuracy to unistroke methods based on stylus input.

In this paper, we explore the use of a projection-based handheld device to facilitate in-clinic doctor-patient communication. We present the user-centered design process used to understand the workflow of medical professionals and to identify challenges they currently face in communicating information to patients. Based on the lessons learned, we developed AnatOnMe, a prototype projection-based hand-held system for enhancing information exchange in the current practice of one medical sub-specialty, physical therapy. We then present the results of a controlled experiment to understand the desirability and learning tradeoffs of using AnatOnMe to teach medical concepts on three potential projection surfaces - wall, model, and patient body. Finally, we present results of two expert reviews of the system.

In this paper, we extrapolate the evolution of mobile devices in one specific direction, namely miniaturization. While we maintain the concept of a device that people are aware of and interact with intentionally, we envision that this concept can become small enough to allow invisible integration into arbitrary surfaces or human skin, and thus truly ubiquitous use. This outcome assumed, we investigate what technology would be most likely to provide the basis for these devices, what abilities such devices can be expected to have, and whether or not devices that size can still allow for meaningful interaction. We survey candidate technologies, drill down on gesture-based interaction, and demonstrate how it can be adapted to the desired form factors. While the resulting devices offer only the bare minimum in feedback and only the most basic interactions, we demonstrate that simple applications remain possible. We complete our exploration with two studies in which we investigate the affordance of these devices more concretely, namely marking and text entry using a gesture alphabet.

The design of virtual environments for applications that have several levels of scale has not been deeply addressed. In particular, navigation in such environments is a significant problem. This paper describes the design and evaluation of two navigation techniques for multiscale virtual environments (MSVEs). Issues such as spatial orientation and understanding were addressed in the design process of the navigation techniques. The evaluation of the techniques was done with two experimental and two control groups. The results show that the techniques we designed were significantly better than the control conditions with respect to the time for task completion and accuracy.

Continued advances in display hardware, computing power, networking, and rendering algorithms have all converged to dramatically improve large high-resolution display capabilities. We present a survey on prior research with large high-resolution displays. In the hardware configurations section we examine systems including multi-monitor workstations, reconfigurable projector arrays, and others. Rendering and the data pipeline are addressed with an overview of current technologies. We discuss many applications for large high-resolution displays such as automotive design, scientific visualization, control centers, and others. Quantifying the effects of large high-resolution displays on human performance and other aspects is important as we look toward future advances in display technology and how it is applied in different situations. Interacting with these displays brings a different set of challenges for HCI professionals, so an overview of some of this work is provided. Finally, we present our view of the top ten greatest challenges in large highresolution displays.

In the late 90’s the emergence of high performance 3D commodity graphics cards opened the way to use PC clusters for high performance Virtual Reality (VR) applications. Today PC clusters are broadly used to drive multi projector immersive environments. In this paper, we survey the different approaches that have been developed to use PC clusters for VR applications. We review the most common software tools that enable to take advantage of the power of clusters. We also discuss some new trends.