Browsing by Author "Xiao, Robert"

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    Analysis and comparison of target assistance techniques for relative ray-cast pointing
    (Elsevier, 2013) Bateman, Scott; Mandryk, Regan L.; Gutwin, Carl; Xiao, Robert
    Pointing at displays from a distance is becoming a common method of interacting with computer applications and entertainment systems, using devices such as the Wii Remote, the PlayStation Move controller, or the Microsoft Kinect. These systems often implement relative forms of ray-cast pointing, in which the user simply points a hand-held input device towards targets on the screen. Ray-casting interaction is easy for novices to learn and understand, but this technique often suffers from accuracy problems: for example, hand jitter, arm fatigue, calibration drift, or lack of skill can all reduce people’s ability to acquire and select on-screen targets. In this paper, we analyse and evaluate the idea of target assistance as a way to address the accuracy problems of ray-cast pointing. Although several assistance schemes have been proposed for mouse-based pointing, these ideas have not been tested in distant-pointing settings, and there is little knowledge available to guide design in this increasingly common interaction scenario. To establish this basic design knowledge, we carried out four studies of relative ray-casting using three different target assistance techniques—two motor-space techniques (sticky targets and a novel form of target gravity), and one acquisition-feedback technique that combined visual, tactile, and auditory feedback. Our first three studies tested each assistance technique separately, to explore how different parameters for each method affected performance and perceptibility. Our fourth study carried out a direct comparison of the best versions of each technique, and also examined the effects of distractor objects placed in the path to the target. Our studies found that the two motor-space techniques were extremely effective in improving selection accuracy without being highly obvious to users, and that the new gravity-based technique (which attracts the cursor even when it is not over the target) performed best of all. There was no observed effect on performance when the combined acquisition-feedback technique was used. Our studies are the first to comprehensively explore the optimization, performance, and perceptibility of target assistance techniques for relative ray-casting—our results provide designers with clear guidelines about what methods to use, how to configure the techniques, and what effects can be expected from their use.
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    Effects of view, input device, and track width on video game driving
    (Canadian Human-Computer Communications Society, 2011) Bateman, Scott; Doucette, Andre; Xiao, Robert; Gutwin, Carl; Mandryk, Regan L.; Cockburn, Andy
    Steering and driving tasks -- where the user controls a vehicle or other object along a path -- are common in many simulations and games. Racing video games have provided users with different views of the visual environment -- e.g., overhead, first-person, and third-person views. Although research has been done in understanding how people perform using a first-person view in virtual reality and driving simulators, little empirical work has been done to understand the factors that affect performance in video games. To establish a foundation for thinking about view in the design of driving games and simulations, we carried out three studies that explored the effects of different view types on driving performance. We also considered how view interacts with difficulty and input device. We found that although there were significant effects of view on performance, these were not in line with conventional wisdom about view. Our explorations provide designers with new empirical knowledge about view and performance, but also raise a number of new research questions about the principles underlying view differences.
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    Investigation of Targeting-Assistance Techniques for Distant Pointing with Relative Ray Casting
    (2010) Bateman, Scott; Mandryk, Regan; Gutwin, Carl; Xiao, Robert
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    Ubiquitous cursor: a comparison of direct and indirect pointing feedback in multi-display environments
    (Canadian Human-Computer Communications Society, 2011) Xiao, Robert; Nacenta, Miguel A.; Mandryk, Regan L.; Cockburn, Andy; Gutwin, Carl
    Multi-display environments (MDEs) connect several displays into a single digital workspace. One of the main problems to be solved in an MDE's design is how to enable movement of objects from one display to another. When the real-world space between displays is modeled as part of the workspace (i.e., Mouse Ether), it becomes difficult for users to keep track of their cursors during a transition between displays. To address this problem, we developed the Ubiquitous Cursor system, which uses a projector and a hemispherical mirror to completely cover the interior of a room with usable low-resolution pixels. Ubiquitous Cursor allows us to provide direct feedback about the location of the cursor between displays. To assess the effectiveness of this direct-feedback approach, we carried out a study that compared Ubiquitous Cursor with two other standard approaches: Halos, which provide indirect feedback about the cursor's location; and Stitching, which warps the cursor between displays, similar to the way that current operating systems address multiple monitors. Our study tested simple cross-display pointing tasks in an MDE; the results showed that Ubiquitous Cursor was significantly faster than both other approaches. Our work shows the feasibility and the value of providing direct feedback for cross-display movement, and adds to our understanding of the principles underlying targeting performance in MDEs.