Research Projects

My main research interests area: information visualization, visual analytics, human-computer interaction, and computer supported-cooperative work.

Collaborative Information Visualization
Stackables Tangibles for faceted search CoCoNutTrix
A study on retrofitting for collaborative information visualization
Cambiera
Collaborative Visual Analytics in document collections
CoTree
Collaborative analysis of hierarchical data
PhD Thesis
Overview and Errata of my PhD Thesis
Coupling styles in collaborative work Design Considerations
for co-located collaborative visualization
A study of data analysis processes in collaborative work iLoupe and iPodLoupe for interacting with visualization on a touch display Lark
Coordinating multiple views for collaboration
Information Visualization Techniques
Hybrid Image Vis
using hybrid images for visualization and communication
PhylloTrees
phyllotactic patterns for tree layout
ArcTrees
relations in hierarchical data
KeyStrokes
personalizing typed text through visualization
IVI
visualization for multimedia databases
DualScaleCharts
a comparative study of several dual-scale charts
GraphEdges
a study on how to best draw directed edges in graphs
Information Visualization Evaluation
Perception of visual variables on tiled wall displays Empirical evaluation in InfoVis: Seven scenarios Evaluation in a large company context Heuristic evaluation for information visualization Grounded evaluation for information visualization
Interaction Techniques for Visualization
MultitouchSelection how to support multi-touch multi-object selection
Non-photorealistic Rendering
NPRLenses
Lenses for illustration.
A study of NPR line illustration (external link) Interactive text illustration
Miscellaneous and Fun Projects
A simple force-directed layout to show my co-authorship network A video coding tool for qualitative data analysis Convenience tool for getting color code for OpenGL programming Applet for calculating the visual angle of an object based on viewing distance. How I built a multi-touch pad from scratch

Research Path

Here is a brief history of how I ended up with the types of projects you see above:

I started research in the area of computer graphics and in particular non-photorealistic rendering (NPR) - a very hot topic at the University of Magdeburg where I studied from 1999-2004. Towards the end of my studies there I got more and more involved in information visualization. First, I worked as a research assistant on applications for visualization of database content & queries and finished my studies in Magdeburg with work on hierarchical data visualization. After my Diplom, I went to the University of Calgary and focused my research more on collaborative information visualization. I also work(ed) on a few projects in other areas such as the evaluation of information visualizations, social data analysis, and the visualization of hierarchical data. Nowadays my research is focused on information visualization, visual analytics, and group work in these areas.