Cartographic design and the space-time cube

This paper reports on the results of an empirical evaluation that aimed to define the effectiveness and efficiency of different visual variables in depicting the Space-Time Cube's content. Existing Space-Time Cube applications demonstrate that the most used visual variables are size and color hue. Less is known, however, about their usability metrics. The research sets design criteria for Space-Time Cube contents, such as space-time paths, based on the cartographic design theory. The visual variables color hue, color value, color saturation, size and orientation have been applied in two different use case studies. Besides, to support the three-dimensional visual environment, depth cues such as shading and transparency were considered too. User tests have been executed based on real world problems with particular attention for the visualization strategy and data complexity. The outcomes revealed the most efficient and effective visual variables to represent data of various complexities in the Space-Time Cube.