Visualizing Code Smells: Tables or Code Cities? A Controlled Experiment

This paper presents a study in which we compared the visualization of code smells in Code Cities with classical tabular representations. We conducted a controlled experiment with 20 participants who had to solve six tasks in both environments. We evaluated the results of our experiment statistically and came to the following conclusions: In four tasks the completion time was significantly lower when using Code Cities (the remaining two tasks did not show any statistically significant differences for any of the two environments). Also, the perceived effort was significantly lower in three tasks when the participants used Code Cities over the tabular representation (again, the remaining tasks did not show any statistically significant differences). However, with regard to the perceived usability (which was measured across all tasks) and the correctness of the supplied answers, the tabular representation performed better. In particular, in two tasks the correctness was significantly better in the tabular environment and in one task the correctness was significantly better in the Code Cities environment. Based on our results, our verdict is as follows: Code Cities are better suited to get a quick overview of the code smells of a software, whereas tabular representations are better suited to analyze code smells in more detail. Experiment data, evaluation scripts and supplemental material: https://github.com/uni-bremen- agst/VISSOFT2022/archive/refs/tags/1.0.0.zip (see README.md in the ZIP archive)