Movement Patterns and Trajectories in Three-Dimensional Software Visualization

Software visualization is a growing field of research, in which developers are assisted in understanding and analyzing complex applications by mapping different aspects of a software system onto visual attributes. Under the assumption that virtual reality, due to the higher degree of immersion, may enhance user experience, researchers have begun to port existing visualization techniques to this environment. Oftentimes, layout algorithms and user interaction methods are more or less transferred one-to-one, though little is known about the effect of virtual reality in visual analytics and program comprehension. Moreover, little research on the behavior of developers in different three-dimensional visualization environments has been done yet. This paper extends the results of a previous controlled experiment, in which the EvoStreets visualization technique was compared in different two-and three-dimensional environments. In the original experiment, we could not find evidence that any of the environments, namely, 2D, 2.5D, and virtual reality, effects the time required to find an answer or the correctness of the given answer. However, we found indications that movement patterns differ between the 2.5D and the virtual reality environments. For this paper, we analyzed and refined the movement trajectories that have been recorded in the previous experiment. We found significant differences for some of the tasks that had to be solved by the participants. In particular, we found evidence that the path length, average speed, and occupied volume differ. Though we could find significant correlations between these metrics and correctness, we found indications that there is a correlation with time, which, in turn, differs significantly between the 2.5D and the VR environments for many tasks. These findings may have implications on the design of visualizations, interactions, and recommendation systems for these different environments.