Evaluating cartographic design principles applied to space-time cube content

The interest and use of the Space-Time Cube (STC) has increased over the last years, because it is a suitable graphic representation of movement related data, emphasizing both space and time. This type of data is abundantly available because of the widespread use of GPS and other location capturing tools. Movement data can be expressed in moves (paths) and stops (stations) and can be found in many applications discussed in literature. However, the visualizations shown in this literature are often not optimal. This can be due to the size and complexity of the data sets, but is often also due to the neglectance of a proper cartographic design. To judge the influence of this design on the effectiveness and efficiency of the STC as a graphic representation of movement data a user-centered design evaluation has been set up. The experiment included two applications each with its own characteristic data complexity and content. It involved a historic and an urban problem case. The first is a relatively simple dataset of historical movements and the second is a complex dataset of pedestrians movement. Based on questions formulated by domain experts different design scenarios were tested. These included the different uses of the graphic variables and depth cues to represent the paths and stations. Both quantitative and qualitative evaluation methods were applied during the testing. The results gave an indication on how design influence the 'performance' of the STC, and resulted in guidelines for the design of the cubes content.