On the Density and Diversity of Degradation Symptoms in Refactored Classes: A Multi-case Study

Unveiling Social and Technical Facets of Design Degradation in Modern Code Review

“…Thus, it would be important to effectively assess the design of changed classes during code review as design problems may arise or become more severe during the review process. For instance, the co-occurrence of various Complex Methods, in the same classes is usually a sign of critical architectural problems, such as Component Overload or Scattered Functionality [29,34].…”

“…There are multiple studies about the perspective of developers about design degradation [28,34,37,69,91]. Other studies focus on the use of diversity and density of symptoms (i.e., code smells) as characteristics of design degradation [29,67,68]. For instance, Sousa et al [34] identified five categories of symptoms upon which developers often rely to identify design problems.…”

“…Similar to other studies [37,40,91], they observed that developers tend to combine multiple symptoms, by considering dimensions such as their density, diversity, and granularity to decide if there is design degradation. Oizumi et al [29] investigated if degradation symptoms appear with higher density and diversity in classes refactored by developers. The authors observed that despite not being always removed by refactorings, some types of symptoms may be indeed strong indicators of design problems.…”

“…More specifically, even though studies have been investigating the impact of modern code review on design quality [11,15,21,24,40], most of them only address the relation between modern code review -and their practices -and design degradation in a constrained manner. Such studies tend to analyze design degradation considering only single events (related to design degradation), such as the introduction of a single design problem [34,37], or simply analyzing the degradation frequency [28,29,41,40].…”

“…Additionally, all symptoms were automatically detected using a state-of-the-practice tool called Designite-Java [4]. This tool is successfully used in recent studies on design degradation (e.g., [29,73]), and prior work [114] indicated a precision of 96% and a recall of 99%.…”