Andreas Kerren

Information Visualization: Human-Centered Issues and Perspectives

General Reflections.- The Value of Information Visualization.- Evaluating Information Visualizations.- Theoretical Foundations of Information Visualization.- Teaching Information Visualization.- Specific Aspects.- Creation and Collaboration: Engaging New Audiences for Information Visualization.- Process and Pitfalls in Writing Information Visualization Research Papers.- Visual Analytics: Definition, Process, and Challenges.

Human-centered visualization environments

What do you do to start reading human centered visualization environments? Searching the book that you love to read first or find an interesting book that will make you want to read? Everybody has difference with their reason of reading a book. Actuary, reading habit must be from earlier. Many people may be love to read, but not a book. Its not fault. Someone will be bored to open the thick book with small words to read. In more, this is the real condition. So do happen probably with this human centered visualization environments.

Enhancing learning management systems to better support computer science education

Many individual instructors -- and, in some cases, entire universities -- are gravitating towards the use of comprehensive learning management systems (LMSs), such as Blackboard and Moodle, for managing courses and enhancing student learning. As useful as LMSs are, they are short on features that meet certain needs specific to computer science education. On the other hand, computer science educators have developed--and continue to develop-computer-based software tools that aid in management, teaching, and/or learning in computer science courses. In this report we provide an overview of current CS specific on-line learning resources and guidance on how one might best go about extending an LMS to include such tools and resources. We refer to an LMS that is extended specifically for computer science education as a Computing Augmented Learning Management System, or CALMS. We also discuss sound pedagogical practices and some practical and technical principles for building a CALMS. However, we do not go into details of creating a plug-in for some specific LMS. Further, the report does not favor one LMS over another as the foundation for a CALMS.

Preserving the mental map using foresighted layout

First we introduce the concept of graph animations as a sequence of evolving graphs and a generic algorithm which computes a Foresighted Layout for dynamically drawing these graphs while preserving the mental map. The algorithm is generic in the sense that it takes a static graph drawing algorithm as a parameter. In other words, trees can be animated with a static tree layouter, graphs with a static Sugiyama-style layouter or a spring embedder, etc. Second we discuss applications of Foresighted Layout in algorithm animation and visualization of navigation behaviour.

Merging interactive visualizations with hypertextbooks and course management

As a report of a working group at ITiCSE 2006, this paper provides a vision of how visualizations and the software that generates them may be integrated into hypertextbooks and course management systems. This integration generates a unique synergy that we call a Visualization-based Computer Science Hypertextbook (VizCoSH). By borrowing features of both traditional hypertextbooks and course management systems, VizCoSHs become delivery platforms that address some of the reasons why visualizations have failed to find widespread use in education.The heart of the paper describes these features and explains, from both a student and teacher perspective, how each feature adds educational value to a visualization. In some cases, this value focuses on pedagogical issues, taking advantage of known strategies for making visualizations more engaging and effective. In other cases, the emphasis is on making it easier for teachers to use visualizations. A set of possible use scenarios and approaches for increasing interest in adopting a VizCoSH are also presented.

MobilityGraphs: Visual Analysis of Mass Mobility Dynamics via Spatio-Temporal Graphs and Clustering

Learning more about people mobility is an important task for official decision makers and urban planners. Mobility data sets characterize the variation of the presence of people in different places over time as well as movements (or flows) of people between the places. The analysis of mobility data is challenging due to the need to analyze and compare spatial situations (i.e., presence and flows of people at certain time moments) and to gain an understanding of the spatio-temporal changes (variations of situations over time). Traditional flow visualizations usually fail due to massive clutter. Modern approaches offer limited support for investigating the complex variation of the movements over longer time periods. We propose a visual analytics methodology that solves these issues by combined spatial and temporal simplifications. We have developed a graph-based method, called MobilityGraphs, which reveals movement patterns that were occluded in flow maps. Our method enables the visual representation of the spatio-temporal variation of movements for long time series of spatial situations originally containing a large number of intersecting flows. The interactive system supports data exploration from various perspectives and at various levels of detail by interactive setting of clustering parameters. The feasibility our approach was tested on aggregated mobility data derived from a set of geolocated Twitter posts within the Greater London city area and mobile phone call data records in Abidjan, Ivory Coast. We could show that MobilityGraphs support the identification of regular daily and weekly movement patterns of resident population.

Text visualization techniques: Taxonomy, visual survey, and community insights

Text visualization has become a growing and increasingly important subfield of information visualization. Thus, it is getting harder for researchers to look for related work with specific tasks or visual metaphors in mind. In this paper, we present an interactive visual survey of text visualization techniques that can be used for the purposes of search for related work, introduction to the subfield and gaining insight into research trends. We describe the taxonomy used for categorization of text visualization techniques and compare it to approaches employed in several other surveys. Finally, we present results of analyses performed on the entries data.

Toward the role of interaction in visual analytics

This paper firstly provides a general introduction in the most important aspects and ideas of Visual Analytics. This multidisciplinary field focuses on the analytical reasoning of typically large and complex (often heterogeneous) data sets and combines techniques from interactive visualizations with computational analysis methods. Hereby, intuitive and efficient user interactions are a fundamental component which has to be efficiently supported by any Visual Analytics system. This integration of interaction techniques into both visual representations and automatic analysis methods supports the human-information discourse and can be realized in various ways which is discussed in the second part of the paper. We give examples of possible applications of Visual Analytics from the domain of biological simulations and highlight the importance and role of the human in the analysis loop.

On open problems in biological network visualization

Much of the data generated and analyzed in the life sciences can be interpreted and represented by networks or graphs. Network analysis and visualization methods help in investigating them, and many universal as well as special-purpose tools and libraries are available for this task. However, the two fields of graph drawing and network biology are still largely disconnected. Hence, visualization of biological networks does typically not apply state-of-the-art graph drawing techniques, and graph drawing tools do not respect the drawing conventions of the life science community. In this paper, we analyze some of the major problems arising in biological network visualization. We characterize these problems and formulate a series of open graph drawing problems. These use cases illustrate the need for efficient algorithms to present, explore, evaluate, and compare biological network data. For each use case, problems are discussed and possible solutions suggested.

The Network Lens: Interactive Exploration of Multivariate Networks Using Visual Filtering

Networks are widely used in modeling relational data often comprised of thousands of nodes and edges. This kind of data alone implies a challenge for its visualization as it is hard to avoid clutter of network elements if using traditional node-link diagrams. Moreover, real-life network data sets usually represent objects with a large number of additional attributes that need to be visualized, such as in software engineering, social network analysis, or biochemistry. In this paper, we present a novel approach, called Network Lens, to visualize such attributes in context of the underlying network. Our implementation of the Network Lens is an interactive tool that extends the idea of so-called magic lenses in such a way that users can interactively build and combine various lenses by specifying different attributes and selecting suitable visual representations.