This dissertation examines how the computer can aid the creative human endeavour which is data visualization. That computers now critically aid many fields is apparent, as is evidenced by the breadth of contemporary research on this topic. Indeed, computers have contributed widely to the whole area of data comprehension, both in performing extensive computations and in producing visual representations of the results. Computers originally aided mathematicians who could both write the instructions necessary to direct the computer and interpret the resulting numbers. Even though modern computers include advanced graphical capabilities, many issues of access still remain: the users of data visualization software systems may not be experts in any computer-related field, yet they want to see visual representations of their data which allow them insight into their problems. For example, today's mathematicians who are generally expert in exploiting computational opportunities for experimentation may lack similar experience in opportunities for visual exploration. Of particular concern is how a computer-aided visualization tool can be designed to support

Due to the continuous drop in computer hardware prices, the use of high-end computer systems has become attractive to many hospitals. Radiology departments are now facing the transition from the use of traditional light screens and photographic films to online medical imaging systems. These new systems offer several advantages over traditional methods: films are less likely to be lost, automatic anomaly detection can improve diagnosis, and high-speed networks allow for cross-site consultations (telemedicine). However, the use of desktop monitors severely limits the space in which medical images can be viewed. This applies particularly to Magnetic Resonance Imaging (MRI) where, frequently, up to eight films, each containing up to 20 images, are viewed simultaneously on a light screen. As a result, the screen real-estate problem inherent in desktop monitors becomes a serious restriction for the radiologists. In a previous requirements analysis, researchers suggested displaying selected images in full resolution with the surrounding images remaining on the screen although reduced in size (called detail-in-context). Based on feedback obtained from this previous research, and

Abstract: This project sets a discussion about possible improvements for mobile menu structuring. Navigation on mobile phones is supposed to get quicker and easier. To reach for better user overview and orientation, the relationship between the single menu items is visualized. To prevent wasting the expensive screen space, icons are used to represent the items. Three different approaches are compared. Image Embedding arranges the content in its context by drawing according background images. The Manhattan Lens Stairs approach is based on human spatial memory abilities. It uses the Manhattan Lens to differ between important and unimportant items. Finally the Dynamic Neighbors approach represents the menu items ’ relationship by using color gradients. To enable a quicker navigation process, important items to display are calculated in every navigation step. Latter is implemented and tested in a user study afterwards. 1

Abstract: This project sets adiscussion about possible improvements for mobile menu structuring. Navigation on mobile phones is supposed to get quicker and easier. To reach for better user overview and orientation, the relationship between the single menu items is visualized. To prevent wasting the expensive screen space, icons are used to represent the items. Three different approaches are compared. Image Embedding arranges the content in its context by drawing according background images. The Manhattan Lens Stairs approach is based on human spatial memory abilities. It uses the Manhattan Lens to differ between important and unimportant items. Finally the Dynamic Neighbors approach represents the menu items ’ relationship by using color gradients. To enable a quicker navigation process, important items to display are calculated in every navigation step. Latter is implemented and tested in auser study afterwards. 1

This paper concerns the design of public displays that project casual awareness information, where passerby’s quickly acquire a sense of who in a small group is around and available. After describing what we mean by casual awareness, we present several prototype designs. In particular, we take awareness information garnered from a small group inhabiting a physical environment and abstract it onto a scene. We use the Three-Dimensional Pliable Surfaces visualization technique to emphasize people’s particular activities.

Detail-in-context lens techniques can be useful for exploring visualizations of data spaces that are too large or have too much detail to fit in regular displays. For example, by bending the space in the right way we can bring together details from two separate areas for easy comparison while roughly keeping the context that situates each area within the global space. While these techniques can be powerful tools, they also introduce distortions that need to be understood, and often the tools have to be disabled in order to have access to the undistorted data. We introduce the undistort lens, a complement to existing distortion-based techniques that provides a local and separate presentation of the original geometry without affecting any distortion-based lenses currently used in the presentation. The undistort lens is designed to allow interactive access to the underlying undistorted data within the context of the distorted space, and to enable a better understanding of the distortions. The paper describes the implementation of a generic back-mapping mechanism that enables the implementation of undistort lenses for arbitrary distortion based techniques, including those presented in the lens literature. We also provide a series of use-case scenarios that demonstrate the situations in which the technique can complement existing lenses.

Abstract—We present the results of a user study that compares different ways of representing Dual-Scale data charts. Dual-Scale charts incorporate two different data resolutions into one chart in order to emphasize data in regions of interest or to enable the comparison of data from distant regions. While some design guidelines exist for these types of charts, there is currently little empirical evidence on which to base their design. We fill this gap by discussing the design space of Dual-Scale cartesian-coordinate charts and by experimentally comparing the performance of different chart types with respect to elementary graphical perception tasks such as comparing lengths and distances. Our study suggests that cut-out charts which include collocated full context and focus are the best alternative, and that superimposed charts in which focus and context overlap on top of each other should be avoided.