What do we know about the space-time cube from cartographic and usability perspective? University of Twente, Faculty of Geo-Information Science and Earth Observation (ITC), 7500 AE Enschede, the Netherlands Irma Kveladze and Menno-Jan Kraak Email: <kveladze; kraak>@Itc.nl ABSTRACT: This paper discusses the results of the extensive usability evaluation of the space-time cube based on a user centered design approach. It is characterized by an early involvement of human geographers, who provided rich movement data and their research questions, to be used in use case scenarios during the testing. With the domain experts workflows were established and linked to a visualization strategy based on Shneiderman’s mantra. With the question ‘What is the effect of the cartographic design on the usability of the space-time cube?’ in mind different maps were created applying different visual variables and depth cues. In a focus group based experiment the design was evaluated with eight experts in geovisualization. During this test the suitability of the visual variables was discussed for the ‘overview’ and ‘zoom’ steps based on several hypotheses. For the display of the trajectories qualitative data the results were as expected. For the quantitative data some surprising result can be reported. The final results are a good starting point for some more testing with alternative data sets. KEYWORDS: Space-time cube, usability evaluation, cartographic design, domain experts Introduction The advancement of the modern technology such as GPS devices and various tracking systems has resulted in the accumulation of large datasets that attracts the interest of many researchers, because they potentially contain rich and useful information about movement behavior. In this context, the visual interpretation of complex trajectories can support understanding of this behavior. As such visualization plays a prominent role to support the process of knowledge discovery, since it facilitates information extraction, and can lead to insight and understanding (Dykes and Mountain, 2003). Many types of visual representations can be used to display movements, among them the Space-Time Cube (STC). It was introduced at the beginning of 1970’s in the then new domain of time geography. During the last decades the interest in this representation has increased considerably because of hard- and software developments, which allow for easy creation and manipulation of the graphics. As a result, more and more specialists in various domains are using STC to visually analyze complex movement datasets. It now is a common representation for visualization of trajectories (Kraak, 2003; Andrienko and Andrienko, 2011), because it is expected that it supports the understanding of the relationships between individual movements and patterns as a whole. Despite of its wide use in analysis and presentation there are some essential unanswered questions related to the usability of the STC (Kraak and Koussoulakou, 2005). Besides, the STC, just as most other graphics can suffer from visual clutter when many trajectories are displayed together. In recent years, the usability of the STC has received attention from researchers in the geovisualization domain. The resulting papers are limited in number and mainly report evaluation experiments that compare the STC with other visual representations. In Proceedings - AutoCarto 2012 - Columbus, Ohio, USA - September 16-18, 2012