Mobile Information Visualization
- FB Informatik und Informationswissenschaft
|(2008): Zoom Interaction Design for Pen-Operated Portable Devices International Journal of Human-Computer Studies ; 66 (2008), 8. - S. 605-627|
Maps are currently the most common application domain for ZUIs. Standard techniques for controlling such interfaces on pen-operated devices usually rely on sequential interaction, i.e. the users can either zoom or pan. A more advanced technique is speed-dependent automatic zooming (SDAZ), which combines rate-based panning and zooming into a single operation and thus enables concurrent interaction. Yet another navigation strategy is to allow for concurrent, but separate, zooming and panning. However, due to the limitations of stylus input, this feature requires the pen-operated device to be enhanced with additional input dimensions. We propose one unimanual approach based on pen pressure, and one bimanual approach in which users pan the view with the pen while manipulating the scale by tilting the device. In total, we developed four interfaces (standard, SDAZ, pressure, and tilting) and compared them in a usability study with 32 participants. The results show that SDAZ performed well for both simple speed tasks and more complex navigation scenarios, but that the coupled interaction led to much user frustration. In a preference vote, the participants strongly rejected the interface and stated that they found it difficult and irksome to control. This result enhances previous research, which in most cases found a high user preference for SDAZ, but focused solely on simple speed tasks. In contrast, the pressure and tilt interfaces were much appreciated, which, considering the novelty of these approaches, is highly encouraging. However, in solving the test tasks the participants took hardly any advantage of parallel interaction. For a map view of 600x600 pixels, this resulted in task-completion times comparable to those for the standard interface. For a smaller 300x300 pixels view, the standard interface was actually significantly faster than the two novel techniques. This ratio is also reflected in the preference votes. While for the larger 600x600 pixels view the tilt interface was the most popular, the standard interface was rated highest for the 300x300 pixels view. Hence, on a smaller display, precise interaction may have an increased impact on the interface usability. Overall, we believe that the alternative interaction techniques show great potential for further development. In particular, a redesign should encourage parallel interaction more strongly and also provide improved support for precise navigation.
|(2008): Navigation Support for Exploring Starfield Displays on Personal Digital Assistants Handbook of Research on User Interface Design and Evaluation for Mobile Technology : / Lumsden, Joanna (Hrsg.). - IGI Global, 2008. - S. 576-593. - ISBN 978-1-59904-872-7|
Due to advances in hardware technologies, mobile devices are increasingly capable of handling largescale data sets. While this development broadens the application scope of smartphones and PDAs, it also means that high information loads must be displayed on very limited screen real estate. A solution to this problem may be provided by starfield displays. Starfield displays maximize the data-pixel ratio by presenting data inside a zoomable 2-D scatterplot. However, a drawback is that once users have zoomed into the information space, they tend to become lost, due to the clipping of orientation cues. The chapter summarizes the research results of recent projects that were conducted to improve the navigation and orientation features of starfield displays on small screens. Several approaches, such as smooth zooming, overview window, and fisheye view, have been implemented and user-tested. The results may support interface designers when targeting mobile devices.
|(2007): Dynamic text filtering for improving the usability of alphasliders on small screens 2007 11th International Conference Information Visualization (IV '07). - IEEE, 2007. - S. 145-149. - ISSN 1550-6037. - ISBN 0-7695-2900-3|
Previous research has shown that Alphasliders are an effective tool for searching an alphabetically sorted list when only limited screen space is available for the graphical user interface. To improve user satisfaction, we propose equipping the widget with a novel text filter to dynamically limit the slider range. In this way, users are supported in locating target items and in identifying records that are missing. The results of a comparative user evaluation run on a Personal Digital Assistant showed that 8 out of 12 participants preferred the filter widget to the classic interface. We further suggest an enhanced Alphaslider design to speed up user interaction.
|(2006): Usability of overview-supported zooming on small screens with regard to individual differences in spatial ability Proceedings of the working conference on advanced visual interfaces. - New York, NY : ACM, 2006. - S. 233-240. - ISBN 1-59593-353-0|
Usability of overview-supported zooming on small screens with regard to individual differences in spatial ability
While zoomable user interfaces can improve the usability of applications by easing data access, a drawback is that some users tend to become lost after they have zoomed in. Previous studies indicate that this effect could be related to individual differences in spatial ability. To overcome such orientation problems, many desktop applications feature an additional overview window showing a miniature of the entire information space. Small devices, however, have a very limited screen real estate and incorporating an overview window often means pruning the size of the detail view considerably. Given this context, we report the results of a user study in which 24 participants solved search tasks by using two zoomable scatterplot applications on a PDA - one of the applications featured an overview, the other relied solely on the detail view. In contrast to similar studies for desktop applications, there was no significant difference in user preference between the interfaces. On the other hand, participants solved search tasks faster without the overview. This indicates that, on small screens, a larger detail view can outweigh the benefits gained from an overview window. Individual differences in spatial ability did not have a significant effect on task-completion times although results suggest that participants with higher spatial ability were slowed down by the overview more than low spatial-ability users.
|(2006): Interaktionsstrategien für Punktdiagramm-Visualisierungen auf kleinen Bilschirmen i-com : Zeitschrift für interaktive und kooperative Medien. - S. 32-37. - ISSN 1618-162X. - eISSN 2196-6826|
Es werden zwei neuartige Systeme zur Darstellung und Exploration großer Datenräume auf kleinen Bildschirmen vorgestellt. Die Basis der Applikationen bildet ein Punktdiagramm, welches aufgrund seiner komprimierten Datenkodierung eine effektive Ausnutzung der Präsentationsfläche kleiner Bildschirme erlaubt. Ein weiterer Vorteil des Diagramms ergibt sich aus seiner Übersichtlichkeit. Selbst unerfahrene Nutzer können Trends und Ausreißer im Datenraum leicht identifizieren.<br />Die beiden vorgestellten Applikationen unterscheiden sich hinsichtlich ihrer Interaktionsstrategien. Das geometrisch-semantische ZUI steht für einen metaphernbasierten, intuitiven Ansatz und erinnert in vielen Eigenschaften an ein Computerspiel. Mittels Zoom kann der Nutzer das Verhältnis von Übersicht und Detail seinem jeweiligen Informationsbedürfnis anpassen. Das alternative Fischauge-Interface bietet hingegen die Möglichkeit einen freidefinierbaren Ausschnitt des Punktdiagramms zu vergrößern. Durch die Verzerrung können unter Erhaltung des Kontexts unübersichtliche Datencluster aufgelöst werden. Der Kontext verschafft dem Nutzer eine bessere Orientierung im Datenraum und ermöglicht zudem zusätzliche Navigationsfunktionalität.
|(2006): User Interaction with Scatterplots on Small Screens : a Comparative Evaluation of Geometric-Semantic Zoom and Fisheye Distortion IEEE Transactions on Visualization and Computer Graphics ; 12 (2006), 5. - S. 829-836. - ISSN 1077-2626|
User Interaction with Scatterplots on Small Screens : a Comparative Evaluation of Geometric-Semantic Zoom and Fisheye Distortion
Existing information-visualization techniques that target small screens are usually limited to exploring a few hundred items. In this article we present a scatterplot tool for Personal Digital Assistants that allows the handling of many thousands of items. The application s scalability is achieved by incorporating two alternative interaction techniques: a geometric-semantic zoom that provides smooth transition between overview and detail, and a fisheye distortion that displays the focus and context regions of the scatterplot in a single view. A user study with 24 participants was conducted to compare the usability and efficiency of both techniques when searching a book database containing 7500 items. The study was run on a pendriven Wacom board simulating a PDA interface. While the results showed no significant difference in task-completion times, a clear majority of 20 users preferred the fisheye view to the zoom interaction. In addition, other dependent variables such as user satisfaction and subjective rating of orientation and navigation support revealed a preference for the fisheye distortion. These findings partly contradict related research and indicate that, when using a small screen, users place higher value on the ability to preserve navigational context than they do on the ease of use of a simplistic, metaphor-based interaction style.
|(2005): ZuiScat : querying and visualizing information spaces on personal digital assistants Proceedings of the 7th international conference on human computer interaction with mobile devices & services [Mobile HCI 2005]. - New York, NY : ACM, 2005. - S. 129-136. - ISBN 1-59593-089-2|
ZuiScat is a visualization concept for querying large information spaces on Personal Digital Assistants (PDA). Retrieval results are presented in a dynamic scatterplot, which is enhanced by geometric and semantic zoom techniques to provide smooth transitions from abstract visual encodings to data content. The same visualization is also used to manage bookmarks and to serve as a powerful query history tool. User feedback suggests that ZuiScat provides intuitive and efficient data access but still needs further improvement in terms of zoom usability and visual mapping.