This article proposes and tests a two-component model for describing and programming the finegrained aspects of non-WIMP interaction. The model combines a data-flow or constraint-like component for the continuous relationships with an event-based component for discrete interactions, which can enable or disable individual continuous relationships. Its key ingredients are the separation of non-WIMP interaction into two components and the framework it provides for communication between the two

Information has become interactive. Information visualization is the design and creation of interactive graphic depictions of information by combining principles in the disciplines of graphic design, cognitive science, and interactive computer graphics. As the volume and complexity of the data increases, users require more powerful visualization tools that allow them to more effectively explore large abstract datasets. This

Large 2D information spaces, such as maps, images, or abstract visualizations, require views at various level of detail: Close ups to inspect details, overviews to maintain (literally) an overview. Users often switch between these views. We discuss how smooth animations from one view to another can be defined. To this end, a metric on the effect of simultaneous zooming and panning is de- fined, based on an estimate of the perceived velocity. Optimal is defined as smooth and efficient. Given the metric, these terms can be translated into a computational model, which is used to calculate an analytic solution for optimal animations. The model has two free parameters: animation speed and zoom/pan trade-off. A user experiment to find good values for these is described.

Never before in history has data been generated at such high volumes as it is today. Exploring and analyzing the vast volumes of data has become increasingly difficult. Information visualization and visual data mining can help to deal with the flood of information. The advantage of visual data exploration is that the user is directly involved in the data mining process. There are a large number of information visualization techniques that have been developed over the last two decades to support the exploration of large data sets. In this star report, we provide an overview of information visualization and visual data mining techniques, and illustrate them using a few examples.

Among existing tools for laying out large collections of visual objects, some perform automatic layouts, possibly following some rules prespecified by the user, e.g., graph layout tools, while others let users specify layouts manually, e.g., CAD design tools. Most of them canonly deal with specific types of visualizations, e.g., graphs, and some of them allow users to view visual objects at various levels of detail, e.g., tree-structure visualization tools. In this paper, we develop techniques that strike a balance between user specification and automatic generation of layouts, work at multiple granularities, and are generally applicable. In particular, we introduce a general framework and layout algorithm that (a) deals with arbitrary types of visual objects, (b) allows objects to be viewed in any one of several different visual representations (at different levels of detail) , and (c) uses a small number of user-specified layouts to guide heuristic decisions for automatically derivin...

Data abstraction techniques are widely used in multiresolution visualization sys-tems to reduce visual clutter and facilitate analysis from overview to detail. How-ever, analysts are usually unaware of how well the abstracted data represent the original dataset, which can impact the reliability of results gleaned from the ab-stractions. In this thesis, we define three types of data abstraction quality measures for computing the degree to which the abstraction conveys the original dataset: the Histogram Difference Measure, the Nearest Neighbor Measure and Statistical Measure. They have been integrated within XmdvTool, a public-domain multiresolution visualization system for multivariate data analysis that supports sampling as well as clustering to simplify data. Several interactive operations are provided, including adjusting the data abstraction level, changing selected regions, and setting the ac-ceptable data abstraction quality level. Conducting these operations, analysts can select an optimal data abstraction level.

This thesis describes a web-based, responsive, zooming and panning visualization system for a full-featured geographic description of the United States. Current web-based map servers provide, from a visualization standpoint, little more than one static image per page, with hyperlinks for navigation; continuous zooming and panning requires locally stored data. Our primary contribution is a multi-threaded, scalable and responsive client-server architecture that responds to user requests as naturally and quickly as possible, regardless of network bandwidth reliability. This architecture can be generalized for use in other applications, including non-geographic ones. To this we add a scalable and exible user interface for navigation of multi-scale geographic data, with intuitive zooming and panning, pop-up feature labels, and a user controlled tree-hierarchy of windows. We build software tools and algorithms for translating the U.S. Census Bureau's TIGER data into a format designed for speedy database retrieval and network delivery, and for generalizing the data into multiple levels of detail. Because of anomalies in the TIGER data, this processing requires some human intervention. v vi Contents Acknowledgments iii Abstract v List of Figures xi List of Tables xiii 1

Information Visualization aims to provide compact graphical presentations and user interfaces for interactively manipulating large numbers of items. We present a simple “data by tasks taxonomy ” then discuss the challenges of providing universal usability, with example applications using geo-referenced data. Information Visualization has been shown to be a powerful visual thinking or decision tool but it is becoming important for services to reach and empower every citizen. Technological advances are needed to deal with user diversity (age, language, disabilities, etc.) but also with the variety of technology used (screen size, network speed, etc.) and the gaps in user’s knowledge (general knowledge, knowledge of the application domain, of the interface syntax or semantic). We present examples that illustrate how those challenges can be addressed. Designers are discovering how to use rapid and high-resolution color displays to present and manipulate large amounts of information in compact and user-controlled ways. Information Visualization can be defined as the use of computer-supported interactive visual representation of abstract data to amplify cognition (Card et al., 1999). The abstract characteristic of the data is what distinguishes Information

One of the scarcest resources in today's computing devices is screen space. This is particularly evident in the emerging pocket-sized devices such as PDAs, cellular tele- and dataphones, twoway pagers and wireless web browsers. In this paper, we introduce a new approach, called the event horizon user interface model that allows us to overcome some of the limitations. The key idea of the proposed model is that the display can be compressed and expanded by moving objects radially farther away or closer to an event horizon in the middle of the screen. In order to study the proposed model in detail, we have built an implementation called Radius for the Palm^TM connected organizer. The current Radius implementation will be illustrated and some future directions outlined.

Placing numerous data objects and their corresponding labels in limited screen space is a challenging problem in information visualization systems. Extending map-oriented techniques, this paper describes static placement algorithms and develops metrics (such as compactness and labeling rate) as a basis for comparison among these algorithms. A control panel facilitates user customization by showing the metrics for alternative algorithms. Dynamic placement techniques that go beyond map-oriented techniques demonstrate additional possibilities. User actions can lead to selective display of data objects and their labels. KEYWORDS Timelines, data object placement, label placement, information visualization, control panel, metrics, visual feedback 1. INTRODUCTION Mapmakers and now, visualization designers have realized that designing effective presentations for abundant information is a difficult task. Part of the problem is the large number of the data objects compared with the limited scr...