Reevaluating stereo and motion cues for visualizing graphs in three dimensions

It has been known for some time that larger graphs can be interpreted if viewed in 3D than in 2D. Both kinetic depth cues and stereoscopic depth cues increase the size of the structure that can be interpreted. However, prior studies were carried out using displays that provided a level of detail far short of what the human visual system is capable of resolving. This is especially problematic because human stereoscopic vision is known to be a super-acuity, it operates best under conditions where fine details are present. Therefore we undertook a graph comprehension study using a very high resolution stereoscopic display. We examined the effect of stereo, kinetic depth and using 3D tubes versus lines to display the links. The results showed a much greater benefit for 3D viewing than previous studies. For example, with both motion and depth cues, unskilled observers could see paths between nodes in 333 node graphs with a better than 10% error rate. Skilled observers could see up to a 1000 node graph with less than a 10% error rate. This represented an order of magnitude increase over 2D display. These findings are discussed in terms of their implications for information display.