"The world is flat and rectangular", at least when it comes to the types of physical screens that we use for representing data and making decisions. The physical screens that we consider when creating visualizations for representing data, making decisions with this data, and learning about our environment, are predominantly flat and rectangular: our mobile phones and tablets, desktops, or even large wall or table displays. Nevertheless, technology is already evolving quickly: curved, bendable, and highly flexible displays, spherical displays, cubed displays, and even drone-based displays have emerged and are commercially available.

These novel types of displays offer new ways to represent and explore data embedded in everyday environments, to communicate and share it. Data communication, through visualization, will be one of the most impactful uses on these future displays, for personal and public use. The rendering of highly personal data is well suited for personalized displays, such as data bracelets, information fabrics, or augmented everyday objects around the home. Public displays with an unusual form factor can be embedded in non-flat architecture or public infrastructure, can be seen from different angles (cubes, spheres), and show information in a way that is more true to the shown data type. As such, these displays also offer lots of opportunities for reaching and engaging the general public.

Thus, non-flat displays obviously come with many new opportunities that need to be explored. However, they also pose perceptual challenges, and it is yet largely unexplored how to actually utilize these novel form factors for data visualizations. In other words, the potential and challenges of these displays for visual data representation remains unexplored.

This Dagstuhl Seminar will pave the road for escaping from the display flatland that characterizes research in visualization, and create a road-map of how to engage with a future in which physical displays will take on a number of different form factors and may become truly ubiquitous. The seminar aims to bring together researchers working in data visualization and fields related to personal informatics, communication, design, as well as ubiquitous, wearable, and mobile computing. It will provide an opportunity for researchers and practitioners to identify the opportunities for a future where visualizations escape from flat and rectangular screens and define a common research agenda for this emerging field.

An immediate goal of this Dagstuhl Seminar is thus to identify opportunities, open problems that need further investigation and to identify priorities for future research in this space. We would like to put an emphasis on the following research questions during the seminar:

• What are new and exciting application scenarios of use for non-flat and non-rectangular displays for data visualization?
• What are new visualization techniques that are possible for non-flat and non-rectangular displays? Do existing techniques need to be adapted?
• How does putting visualizations on non-flat and non-rectangular displays impact how we understand and use them (i.e., affect our perception and decision making)? How can we study this impact?
• What are the challenges in designing and prototyping visualizations for non-flat and non-rectangular displays? How can we address them?

The outcomes of the seminar and our discussions aim to have an impact on visualization research and fields related to communication, design, and to ubiquitous, wearable, and mobile computing.

Creative Commons BY 4.0

Anastasia Bezerianos, Raimund Dachselt, and Wesley J. Willett