[国際会議] Characterising the Knowledge about Primitive Variables in Java Code Comments

小林研に準客員若手研究員として滞在していた Alghamdi さんが,オンライン開催された IEEE/ACM 18th Mining Software Repositories Conference (MSR 2021)にて研究発表を行いました.

Alghamdiさんが,The University of Adelaide にて行っている博士研究の一部を構成する内容を小林研で実施したもので,小林研,本学院の林研究室,The University of Adelaide の Dr. Treudeの研究チームとの共同研究の成果です.

著者: Mahfouth Alghamdi, Shinpei Hayashi, Takashi Kobayashi, Christoph Treude
題目: Characterising the Knowledge about Primitive Variables in Java Code Comments
掲載誌: Mining Software Repositories Conference (MSR 2021), Technical Track, pp.460-470, 17-19 May 2021
概要:
Primitive types are fundamental components available in any programming language, which serve as the building blocks of data manipulation. Understanding the role of these types in source code is essential to write software. Little work has been conducted on how often these variables are documented in code comments and what types of knowledge the comments provide about variables of primitive types. In this paper, we present an approach for detecting primitive variables and their description in comments using lexical matching and advanced matching. We evaluate our approaches by comparing the lexical and advanced matching performance in terms of recall, precision, and F-score, against 600 manually annotated variables from a sample of GitHub projects. The performance of our advanced approach based on F-score was superior compared to lexical matching, 0.986 and 0.942, respectively. We then create a taxonomy of the types of knowledge contained in these comments about variables of primitive types. Our study showed that developers usually documented the variables’ identifiers of a numeric data type with their purpose (69.16%) and concept (72.75%) more than the variables’ identifiers of type String which were less documented with purpose (61.14%) and concept (55.46%). Our findings characterise the current state of the practice of documenting primitive variables and point at areas that are often not well documented, such as the meaning of boolean variables or the purpose of fields and local variables.