Utilization of variation in stereoscopic depth for encoding aspects of non-spatial data

In this paper, we present our experience in utilizing the stereoscopic depth for highlighting the structural relations in compound graphs. In this regard, we use the stereoscopic depth to encode the different levels-of-details in compound graphs and the interaction operations provided by the ExpanD technique for expanding or contracting the nodes in order to align graph nodes in the 3D space with minimum occlusion. We conducted a controlled evaluation study where we invited 30 participants to evaluate the approach using different configurations with different graph sizes and different visual clues. The aim of the study was to understand the viewers´ ability in detecting the variations in the stereoscopic depth. The study results show that stereoscopic depth can be used to encode data aspects of graphs under certain circumstances.