Set systems are the generic data model for families of sets. A set is a collection of unique objects, called elements. An element may have attributes, membership functions, and rules. Such a complex data model asks for appropriate exploration methods. As with many types of data, set systems can vary over time and space. It is important, however, not to treat time and space as usual variables. Their special characteristics such as different granularities, time primitives (time points vs. intervals), hierarchies of geographic or administrative regions need to be taken into account. Visualizing and analyzing such changes is challenging due to the size and complexity of the data sets.

Sets systems can also be seen as hypergraphs where the vertices represent the ground elements and the edges are the sets. However, compared to conventional graphs that represent only binary relations (that is, sets with two elements), the visualization of general hypergraphs has received little attention. This is even more so when dealing with dynamic hypergraphs or hypergraphs that represent spatial information.

The main goal of this Dagstuhl Seminar is to foster co-operation and share knowledge between researchers with interests in set visualization coming from various different communities. Useful and usable set visualization can help us to better understand the underlying relationships in real-world categorical data sets. It can also allow for the discovery of patterns and the forecast of future trends in increasingly non-quantitative open datasets available online. Most existing approaches, methods, and tools, however, focus on static set systems and are limited in taking the complexity of temporal and geospatial characteristics into account. Therefore, we want:

1. To bring together researchers working on visualization (i) from a theoretical point of view (graph drawing, computational geometry, and cognition), (ii) from a temporal point of view (visual analytics and information visualization over time, HCI), and (iii) from a space-time point of view (cartography, GIScience).
2. To identify specific theoretical and practical problems that need to be solved in order to create dynamic and interactive set visualizations that take into account time and space. (We want to begin working on these problems during the seminar.)
3. To formulate our findings as first steps to solving the problems under consideration and to define future research directions.

The format of the seminar will allow for presentations as well as planned and ad-hoc problem- solving sessions, with the intention of promoting exchange between the participants of diverse scientific backgrounds and to encourage the work on specific open problems. The first 1.5 days will be reserved for overview presentations from representatives of the different communities, for presenting open problems, and for forming interdisciplinary working groups that will focus on some of the identified open problems as a group. The remaining three days will comprise of working-group meetings and progress reports.

Creative Commons BY 3.0 DE

Sara Irina Fabrikant, Silvia Miksch, and Alexander Wolff

• Hugo Akitaya (Tufts University - Medford, US) [dblp]
• Gennady Andrienko (Fraunhofer IAIS - Sankt Augustin, DE) [dblp]
• Natalia V. Andrienko (Fraunhofer IAIS - Sankt Augustin, DE) [dblp]
• Michael A. Bekos (Universität Tübingen, DE) [dblp]
• Susanne Bleisch (FH Nordwestschweiz - Muttenz, CH) [dblp]
• Steven Chaplick (Universität Würzburg, DE) [dblp]
• Sabine Cornelsen (Universität Konstanz, DE) [dblp]
• Somayeh Dodge (University of Minnesota - Minneapolis, US) [dblp]
• William Evans (University of British Columbia - Vancouver, CA) [dblp]
• Sara Irina Fabrikant (Universität Zürich, CH) [dblp]
• Fabian Frank (University of Arizona - Tucson, US)
• Panos Giannopoulos (City - University of London, GB) [dblp]
• Jan-Henrik Haunert (Universität Bonn, DE) [dblp]
• Michael Kaufmann (Universität Tübingen, DE) [dblp]
• Philipp Kindermann (Universität Würzburg, DE) [dblp]
• Stephen Kobourov (University of Arizona - Tucson, US) [dblp]
• Giuseppe Liotta (University of Perugia, IT) [dblp]
• Eva Mayr (Donau-Universität Krems, AT) [dblp]
• Tamara Mchedlidze (KIT - Karlsruher Institut für Technologie, DE) [dblp]
• Wouter Meulemans (TU Eindhoven, NL) [dblp]
• Silvia Miksch (TU Wien, AT) [dblp]
• Martin Nöllenburg (TU Wien, AT) [dblp]
• Yoshio Okamoto (The University of Electro-Communications - Tokyo, JP) [dblp]
• Margit Pohl (TU Wien, AT) [dblp]
• Peter Rodgers (University of Kent - Canterbury, GB) [dblp]
• André Schulz (FernUniversität in Hagen, DE) [dblp]
• André Skupin (San Diego State University, US) [dblp]
• Christian Tominski (Universität Rostock, DE) [dblp]
• Alexander Wolff (Universität Würzburg, DE) [dblp]