On GitHub, one of the most successful services for software project hosting, labels have been used to represent various information and decisions about reported issues. However, previous studies on labels were limited to simple statistics or label recommendations for issue types. In this paper, we aim to provide a better understanding of labels and their usage in software development. We particularly focus on using multiple and custom labels on issues. To analyze label usage, we collected software project data and label usage information from GitHub. We then quantitatively investigated the performance of projects with multi-label features and qualitatively investigated the categories of multi-labels, and the usage of multi-labels based on these categories. Our analysis results show that multi-labels are common in the majority of software projects and that projects using multi-label features manage their issues more effectively. In addition, our analysis results reveal different types of information represented by labels, which are related to features, development, and issues. This study finds several facts that can be used for studies on issue management and thus that help develop labeling techniques to mitigate the burden of issue management.

The foundational technique of code similarity detection, which underpins plagiarism detection tools, has already reached a level of maturity where it can be effectively employed for practical applications, demonstrating commendable performance. However, although the understanding of code clones—referred to as similar codes—has evolved, there has been a noticeable decline in the emergence of novel proposals for code similarity detection techniques. The landscape of code similarity detection techniques is diverse and can be divided based on how codes are represented. Each method, designed to cater to different types of detectable code similarity instances, has distinct advantages and drawbacks. Therefore, the selection of an appropriate method is crucial and is contingent on the specific objectives of the analysis. This paper provides a comprehensive exploration of code similarity detection techniques and illuminates the prevailing trends in plagiarism detection research. It acquaints readers with a spectrum of distinct code similarity detection methods, accompanied by the requisite contextual background knowledge. Additionally, it presents a detailed overview of the trajectory of research trends in plagiarism detection.

An Issue Tracking System (ITS) plays a crucial role in software development and provides valuable information for understanding issue management. In an ITS, software developers often discuss issues that are reported during software development. Recent studies analyzed such issue discussions and identified information types of issue comments that appeared in the discussions. Automatic classification of the information types can help developers understand and locate required information more easily, but existing techniques cannot provide accurate classification. In this study, we propose a more accurate technique to classify information types of issue comments. The key to increasing classification performance is employing random oversampling to deal with imbalances among training instances of different information types. With random oversampling, we trained a classifier using logistic regression with hyperparameter tuning and achieved an average 0.95 F1-score, which was much higher than 0.53 of the compared existing technique. We also considered two other key aspects of the technique to fully investigate the potential performance improvement. We expanded an existing issue comment dataset by adding 4,098 more instances, almost double the size of the dataset. We analyzed the influence of hyperparameters on classification performance and found that using values within an appropriate range is important to achieve high performance.