Quantifying the Effects of Smooth View Transitions on Perceptual Constancy in Node-Link Diagrams

Many visualization systems use smoothly animated transitions to help the user interact with information structures. These transitions are intended to preserve perceptual constancy during viewpoint transformations, and to aid in the overall understanding of the dataset. However, animated transitions also have costs –they increase the transition time, and they can be complicated to implement – and it is not clear whether the benefits of smooth transitions outweigh the costs. In order to quantify these benefits, we carried out four experiments that explore the effects of smooth transitions. In the first study, subjects were asked to determine whether graph nodes were connected, and navigated the graph either with or without smooth scene transitions. In the second study, participants were asked to identify the overall structure of a tree after navigating the tree through a viewport that either did or did not use smooth transitions for view changes. The third experiment was similar to the second experiment, but removed the bias created by smooth transitions by giving the subjects total control on the directionality of movement. Finally the fourth experiment tested the subject’s performance in a zooming interface that used smooth transitions while transiting between the zoom-in and zoom-out views. The results of all four experiments show that smooth transitions can have dramatic benefits for user performance – for example, participants in smooth transition conditions make half the errors of the discrete-movement conditions. In addition, short transitions were found to be as effective as long ones, suggesting that some of the costs of animations can be avoided. These studies put intuitions about the value of smooth transitions on an empirical footing, and provide practical guidelines about when designers should use them in visualization systems.