Comparing the EvoStreets Visualization Technique in Two-and Three-Dimensional Environments A Controlled Experiment

Analyzing and maintaining large software systems is a challenging task due to the sheer amount of information contained therein. To overcome this problem, Steinbrückner developed a visualization technique named EvoStreets. Utilizing the city metaphor, EvoStreets are well suited to visualize the hierarchical structure of a software as well as hotspots regarding certain aspects. Early implementations of this approach use three-dimensional rendering on regular two-dimensional displays. Recently, though, researchers have begun to visualize EvoStreets in virtual reality using head-mounted displays, claiming that this environment enhances user experience. Yet, there is little research on comparing the differences of EvoStreets visualized in virtual reality with EvoStreets visualized in conventional environments. This paper presents a controlled experiment, involving 34 participants, in which we compared the EvoStreet visualization technique in different environments, namely, orthographic projection with keyboard and mouse, 2.5D projection with keyboard and mouse, and virtual reality with head-mounted displays and hand-held controllers. Using these environments, the participants had to analyze existing Java systems regarding software clones. According to our results, it cannot be assumed that: 1) the orthographic environment takes less time to find an answer, 2) the 2.5D and virtual reality environments provide better results regarding the correctness of edge-related tasks compared to the orthographic environment, and 3) the performance regarding time and correctness differs between the 2.5D and virtual reality environments.