Browsing by Author "Silva, Mara G."
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- BABES: Brushing+Linking, Attributes, and Blobs Extension to StoryboardJudge, Tejinder K.; Kopper, Regis; Ponce, Sean; Silva, Mara G.; North, Christopher L. (Department of Computer Science, Virginia Polytechnic Institute & State University, 2008)In this day and age, people not only deal with data but deal with vast amounts of data which needs to be sorted and made sense of. A subset of these people are intelligence analysts who sort through an enormous amount of data that need to be organized to uncover plots and subplots. We are proposing a tool called BABES (Brushing+Linking, Attributes, and Blobs Extension to Storyboard) that will enable the intelligence analyst to sort through data efficiently, uncover plots and subplots using the brushing and linking and attributes features and work with multiple subplots at the same time using the concept of ’blobs’.
- A Human Motor Behavior Model for Direct Pointing at a DistanceKopper, Regis; Bowman, Douglas A.; Silva, Mara G. (Department of Computer Science, Virginia Polytechnic Institute & State University, 2008-12-01)Models of human motor behavior are well known as an aid in the design of user interfaces (UIs). Most current models apply primarily to desktop interaction, but with the development of non-desktop UIs, new types of motor behaviors need to be modeled. Direct Pointing at a Distance is such a motor behavior. A model of direct pointing at a distance would be particularly useful in the comparison of different interaction techniques, because the performance of such techniques is highly dependent on user strategy, making controlled studies difficult to perform. Inspired by Fitts’ law, we studied four possible models and concluded that movement time for a direct pointing task is best described as a function of the angular amplitude of movement and the angular size of the target. Contrary to Fitts’ law, our model shows that the angular size has a much larger effect on movement time than the angular amplitude and that the growth in the difficulty of the tasks is quadratic, rather then linear. We estimated the model’s parameters experimentally with a correlation coefficient of 96%.
- Increasing the Precision of Distant Pointing for Large High-Resolution DisplaysKopper, Regis; Silva, Mara G.; McMahan, Ryan Patrick; Bowman, Douglas A. (Department of Computer Science, Virginia Polytechnic Institute & State University, 2008-09-01)Distant pointing at large displays allows rapid cursor movements, but can be problematic when high levels of precision are needed, due to natural hand tremor and track-ing jitter. We present two ray-casting-based interaction techniques for large high-resolution displays – Absolute and Relative Mapping (ARM) Ray-casting and Zooming for Enhanced Large Display Acuity (ZELDA) – that ad-dress this precision problem. ZELDA enhances precision by providing a zoom window, which increases target sizes resulting in greater precision and visual acuity. ARM Ray-casting increases user control over the cursor position by allowing the user to activate and deactivate relative map-ping as the need for precise manipulation arises. The results of an empirical study show that both approaches improve performance on high-precision tasks when compared to basic ray-casting. In realistic use, however, performance of the techniques is highly dependent on user strategy.
- Literature Survey on Interaction Techniques for Large DisplaysBadillo, Brian; Bowman, Douglas A.; McConnel, William; Ni, Tao; Silva, Mara G. (Department of Computer Science, Virginia Polytechnic Institute & State University, 2006)When designing for large screen displays, designers are forced to deal with cursor tracking issues, interacting over distances, and space management issues. Because of the large visual angle of the user that the screen can cover, it may be hard for users to begin and complete search tasks for basic items such as cursors or icons. In addition, maneuvering over long distances and acquiring small targets understandably takes more time than the same interactions on normally sized screen systems. To deal with these issues, large display researchers have developed more and more unconventional devices, methods and widgets for interaction, and systems for space and task management. For tracking cursors there are techniques that deal with the size and shape of the cursor, as well as the “density” of the cursor. There are other techniques that help direct the attention of the user to the cursor. For target acquisition on large screens, many researchers saw fit to try to augment existing 2D GUI metaphors. They try to optimize Fitts’ law to accomplish this. Some techniques sought to enlarge targets while others sought to enlarge the cursor itself. Even other techniques developed ways of closing the distances on large screen displays. However, many researchers feel that existing 2D metaphors do not and will not work for large screens. They feel that the community should move to more unconventional devices and metaphors. These unconventional means include use of eye-tracking, laser-pointing, hand-tracking, two-handed touchscreen techniques, and other high-DOF devices. In the end, many of these developed techniques do provide effective means for interaction on large displays. However, we need to quantify the benefits of these methods and understand them better. The more we understand the advantages and disadvantages of these techniques, the easier it will be to employ them in working large screen systems. We also need to put into place a kind of interaction standard for these large screen systems. This could mean simply supporting desktop events such as pointing and clicking. It may also mean that we need to identify the needs of each domain that large screens are used for and tailor the interaction techniques for the domain.