Towards an understanding of dynamics in information visualization

Abstract: This work is about interaction. Research in the field of information visualization has traditionally been slanted more towards presentation; this even though humans are interactive creatures. We observe our surroundings, make decisions based on what we see and react back into the world. It may all have had its modest beginnings on the primordial Xerox Parc desktop but user interfaces of today are becoming more and more faithful representations of our everyday environments. Between the promise of augmented reality and ubiquitous computing, who knows where we are headed. One thing is certain however; whatever world we end up in, we will continue to interact with visual devices. Three papers make up this thesis: Three-dimensional user interfaces are often considered worse than two dimensional from a usability standpoint due to the difficulties imposed by the need to navigate in three dimensions. The first paper of this thesis compares two user interfaces for the visualization of hierarchies, one two-dimensional and one three-dimensional. As we expected the three-dimensional tool excelled at tasks related to hierarchical depth while, surprisingly, the two tools perform comparably on most other tasks. A possible explanation for this is that we restrict manipulation in such a way that the user simply cannot get lost while navigating. Abrupt transitions cause confusion. This is a well known fact and in our second user study we set out to investigate what effect animated transitions would have on navigation in a 3D file system visualizer. The study we conducted failed to show an effect on user performance but did find an effect on navigation patterns. Participants were tasked to navigate stepwise into a directory and then, starting at the root, try to return to it (whichever way they chose). Participants in the animated treatment group were nearly four times as likely to take a shortcut back while participants in the non-animated group overwhelmingly favored a stepwise return strategy. The stepwise approach appears safer in that a percentage of shortcut attempts fail; failures which it seems difficult to recover from. The third and last paper is a survey and taxonomy of interactive animation in user interfaces. User interface animations are becoming more and more prevalent and advanced. Yet there is little in the way of research showing when you should animate and why. In the model underlying the taxonomy a number of aspects of animation are identified. Animation generally has a purpose, animation may catch attention, explain, smooth out abrupt transitions as well as reveal the progress of otherwise hidden processes. There is also a difference between transitional animations that preserve context and those that do not; a fact which is often overlooked. Of the user studies surveyed many show some benefit of animation but a significant number also show distinctly negative effects. Animation has been found to lead to superficial learning and poor retention when applied to teaching, as well as when it is used to smooth out abrupt transitions.