A Dataset of Atoms of Confusion in the Android Open Source Project

Ensuring the readability and comprehension of source code is key for effective software maintenance and evolution, particularly in tasks involving bug fixing, refactoring, and optimization. Previous studies highlight that challenges in maintenance and the emergence of certain bugs can be traced back to small code fragments called "Atoms of Confusion" (AC). While initial investigations identified these snippets in C++ code bases, subsequent studies have identified analogous structures in languages such as Java. Although numerous studies have delved into observing ACs in Java projects, there is a lack of studies focused on the Android ecosystem. This paper aims to address this gap by constructing a comprehensive dataset, which catalogs ACs and assesses their prevalence in the Android Open Source Project (AOSP). After analyzing over 125,000 source code files across 370 Git repositories, our findings reveal that more than 30% of Java files within the AOSP contain at least one AC, totaling over 320,000 recorded instances. This equates to one AC for approximately every 91 lines of code. Particularly, this dataset can be used to support further studies on shedding light on the ACs prevalence in the Android ecosystem, alongside their relation with traditional object-oriented software metrics (e.g., size, complexity, cohesion, and coupling), also recorded in the dataset. Using this dataset, researchers may provide valuable insights for developers and software engineers, emphasizing the need for strategies to mitigate the possible impact of ACs on software maintenance.CCS CONCEPTS•General and reference → Empirical studies; • Software and its engineering → Maintaining software; Software defect analysis; • Human-centered computing → Collaborative interaction.