Information visualizations must allow users to browse information spaces and focus quickly on items of interest. Being able to see some representation of the entire information space provides an initial gestalt overview and gives context to support browsing and search tasks. However, the limited number of pixels on the screen constrain the information bandwidth and make it difficult to completely display large information spaces. The Information Mural is a two-dimensional, reduced representation of an entire information space that fits entirely within a display window or screen. The mural creates a miniature version of the information space using visual attributes such as grayscale shading, intensity, color, and pixel size, along with anti-aliased compression techniques. Information Murals can be used as stand-alone visualizations or in global navigational views. We have built several prototypes to demonstrate the use of Information Murals in visualization applications; subject matter ...

: Perspective projection is generally accepted as the ideal model of image formation. Many recent algorithms, and many recent judgements about the relative merits of different algorithms, depend on this assumption. However, perspective projection represents only the front half of the viewing sphere and it distorts the shape and intensity of objects unless they lie near the optical axis. It is only one of several projections used in lens design and it does not accurately model the behavior of many real lenses. It works well only for narrow-angle images. This paper surveys the properties of several alternative models of image formation. A model based on stereographic projection of the viewing sphere is shown to be a better general-purpose imaging model than perspective projection. The new model can represent wider fields of view and more closely approximates real wide-angle lenses. It preserves a suitable range of shape properties, including local symmetries. It approximates narrow-angl...

This paper studies the creation of schematic maps from traditional vector-based, cartographic information. An algorithm is proposed to modify positions of lines in the original input map with the goal of producing as output a schematic map that meets certain geometric and aesthetic criteria. Special emphasis is placed here on preserving topological structure of features during this transformation. The known, existing methods for preserving topology during map transformation generally involve computing several constrained Delaunay triangulations [Mo189, Go194, JBW95, Rua95]. The algorithm proposed here computes a transformation which preserves topological relations among linear features using simple geometric operations and tests.

In-vehicle navigation has changed substantially in recent years, due to the advent of computer generated maps and directions. However, these maps are still problematic, due to a mismatch between the complexity of the maps and the attentional demands of driving. In response to this problem, we are developing the MOVE (Maps Optimized for Vehicular Environments) system. This system will provide situationally appropriate map information by presenting information that uses appropriate amounts of the driver’s attention. In this paper, we describe our findings of studies to help shape the design of the MOVE system, including studies on map reading and in-vehicle navigation, and studies on the effectiveness of a variety of contextually optimized route map visualizations in a simulated driving context. Results show that contextually optimized displays designed for the MOVE system should significantly reduce perceptual load in the context of driving. In our laboratory experiment there was a six-fold decrease in the total map display fixation time and nearly threefold decrease in the number of glances needed to interpret the contextually optimized display compared to a static display. Author Keywords Maps, in-car navigation systems, visualization, human

This paper reviews current approaches to designing virtual environments and investigates aspects of influence in designing auditory spaces to support novel forms of interaction in virtual places. Initial research on human imagined sounds from places has identified `expectation' as an important psychological construct, which must be considered when designing sounds for virtual places. The research work continues to provide evidence that there are differences between sounds people expect to hear in places and sounds recorded in real life places. Instead of designing realistic virtual spaces, the paper suggests a user's sense of presence as a measure of the user's experience in virtual environment. The results indicate that using highly expected sounds increases users' sense of presence. As such, it is to propose that designing auditory spaces using expectations as perceived affordance is perhaps a minimal way to design auditory spaces that support sense of place, hence provoke the emergence of virtual communities. Future work of the project is discussed.

One feature of modernism is that it artificially separates technology from society. But the notion of two collectives inherent in such an idea presents IS researchers and others with problems of representation that tend to favour one over the other. Thus we see the emergence of conflicting theories: technological determinism on the one hand, theories about the social shaping of technology on the other. Nor do traditional sociotechnical approaches ameliorate these difficulties, since they still regard technology and society as fundamentally separate entities demanding and requiring different treatments. Here we present a process model based on networks-of-association (sometimes called actor network theory), which allows us to work with the single collective that is absolutely necessary if we are to develop a true sociotechnical approach. The Van Sant satellite map of the Earth provides an analogy for information systems design and construction, as well as a means of illust...

This paper summarizes research (Sieber 1997a) that constructed an infrastructure for necessary and sufficient characteristics of effective GIS usage by small environmental nonprofits. This infrastructure then suggested roles for interested external parties. It combined a review of literature on GIS implementation/data sharing and social movement issues with fieldwork. Fieldwork began with a mail survey of computer usage of 100 environmental groups. The survey included questions on software and applications, implementation issues, financial and organizational costs, future computer plans, data sources, and map and GIS "literacy." Seventy four mail survey responses and 25 expert interviews with vendors and conservation GIS leaders assisted in locating five cases for in-depth study of GIS usage. The case study research assessed GIS applications, implementation, spatial data acquisition and sharing, and the contribution of GIS to organizational goals and missions. Work was conducted in California and the Pacific Northwest over a two-year period. Applications of GIS and Computing Technology

This thesis proposes the creation of a scalable architecture to support the access and creation of Location Linked Information--- the coupling of physical location with arbitrary virtual information nuggets. The proposed system dynamically links a physical space/time moment with a distributed database containing information that describes that moment's surroundings. This hybrid virtual/physical space, called glean space, is owned, managed, and rated by the public, for the benefit of the populace. Imagined as initially being embodied by an interactive, dynamic map viewed on a handheld computer, the system provides two functions for its urban users: 1) the retrieval of information about their surroundings, and 2) the optional annotation of location for communal benefit. It is our hypothesis that Location Linked Information will enhance the urban experience, just as access to transportation dramatically altered the sensation and form of the city. By making inhabitants hyper-aware of their surroundings, they get the benefits of a small town citizen (omniscience of space and society) while possibly being situated in a much larger megalopolis with the social mobility and features that go with it. MOTIVATION The city of bits forgot about its atoms As ubiquitous computing moves from theory to practice, the once-clear demarcation between the virtual and the real worlds is increasingly difficult to visualize, especially when visiting real-world mainstays such as urban streets. The deployment of wireless networking technologies such as Wi-Fi and GPRS in these outdoor arenas is accelerating the permeation of digital data

We present a general concept for the enhancement of visual interfaces with automatic figure captions describing a visualization. The incorporation of figure captions in interactive systems raises some fundamentally new questions as these images are exposed to changes. The dynamic aspects to be considered include the update and customization of figure captions. We employ figure captions not only for the description of images but also for their modification leading to the introduction of interactive figure captions. A general architecture is developed and comprehensively described referring to two application domains: medical illustrations and geographic maps. Keywords: Dynamic figure captions, interactive figure captions, medical illustrations, geographic maps 1 INTRODUCTION Visualizations are produced to enable a viewer to extract information. For this purpose, visualizations are not merely a straightforward rendering of the data. Limited presentation space imposes restrictions to the...

Feminist geography and geographic information systems (GIS) have been two of the most dynamic research areas in geography over the past decade. They have opened up new methodologies and epistemologies, challenged fundamental research categories, and charted new areas of geographical inquiry. For the most part, however, these two � elds have remained stubbornly apart—unconnected, uncommunicative, and directing geography in divergent directions. This article, like the others in this collection, explores the connections between feminist geography and GIS, identifying how each can enrich and inform the other. The discussion re � ects my background as a feminist with expertise in GIS and quantitative methodologies and several years ’ experience in using GIS in the health arena. To set the stage for the discussion, I begin with a brief ‘story ’ (case study) describing the role of GIS in women’s activism concerning breast cancer in Long Island, New York. Subsequent sections review the key elements of feminist and GIS epistemologies and then discuss the challenges of integrating the re � exive methodologies of feminism with the more static, layer-based approaches of GIS. Key issues of knowledge, context and power are examined.