IMPROVING DETECTION PERFORMANCE OF DUPLICATE BUG REPORTS USING EXTENDED CLASS CENTROID INFORMATION

Bug deduplication is a hot topic in software engineering information retrieval research, but it is often not deployed. Typically to de-duplicate bug reports developers rely upon the search capabilities of the bug report software they employ, such as Bugzilla, Jira, or Github Issues. These search capabilities range from simple SQL string search to IR-based word indexing methods employed by search engines. Yet too often these searches do very little to stop the creation of duplicate bug reports. Some bug trackers have more than 10\% of their bug reports marked as duplicate. Perhaps these bug tracker search engines are not enough? In this paper we propose a method of attempting to prevent duplicate bug reports before they start: continuous querying. That is as the bug reporter types in their bug report their text is used to query the bug database to find duplicate or related bug reports. This continuous querying allows the reporter to be alerted to duplicate bug reports as they report the bug, rather than formulating queries to find the duplicate bug report. Thus this work ushers in a new way of evaluating bug report deduplication techniques, as well as a new kind of bug deduplication task. We show that simple IR measures show some promise for addressing this problem but also that further research is needed to refine this novel process that is integrate-able into modern bug report systems.

Bug handling is an essential part of the software development process. Ideally, in a bug‐tracking system, bugs are reported, fixed, verified, and closed. In some cases, bugs have to be reopened mostly due to an incorrect fix. However, instead of reopening the existing bug report, users may submit a new report for a previously reported bug, which results in duplicate bug reports. Users might report duplicate bugs if they miss the previous bug report or if the previous bug is unresolved (i.e., in progress) and therefore cannot be reopened. These duplicate bug reports may cost extra maintenance efforts in triaging and bug fixing. There have been several studies on characterizing reopened bugs and duplicate bug reports; however, to the best of our knowledge, there has been no prior work on understanding the dynamics of their interaction, which ismissed reopenbugs. Our study is based on analyzing the difference between duplicate and nonduplicate bugs and further categorizing the duplicate bugs. In this regard, we categorize duplicate bugs according to the original bug's resolution status at the duplicate's creation time as Master‐Unresolved bugs and Master‐Resolved (Missed Reopen) bugs to distinguish their properties. We compare these two types of bugs in terms of their relationship to their master bug, bug surface time, bug fix time, bug's severity, and the number of users involved. We perform case studies using the Eclipse and Mozilla projects' bug repositories that include more than 165,500 and 394,000 bug reports, respectively. Additionally, we investigate the perceived importance, impact, and causes of duplicate bugs, as well as the difference between nonduplicate and duplicate bugs and its categories for practitioners in the software industry by conducting a survey.

Free/Open Source Software (FOSS) communities often use open bug reporting to allow users to participate by reporting bugs. This practice can lead to more duplicate reports, as users can be less rigorous about researching existing bug reports. This paper examines how FOSS projects deal with duplicate bug reports. We examined 12 FOSS projects: 4 small, 4 medium and 4 large, where size was determined by number of code contributors. First, we found that contrary to what has been reported from studies of individual large projects like Mozilla and Eclipse, duplicate bug reports are a problem for FOSS projects, especially medium-sized, which struggle with a large number of submissions without the resources of large projects. Second, we found that the focus of a project does not affect the number of duplicate bug reports. Our findings indicate a need for additional scaffolding and training for bug reporters.

Does Deep Learning improve the performance of duplicate bug report detection? An empirical study

Bug reporting is an uncoordinated process that is often the cause of redundant workload in triaging and fixing bugs due to many duplicated bug reports. Furthermore, quite often, same bugs are repeatedly reported as users or testers are unaware of whether they have been reported from the search query results. In order to reduce both the users and developers' efforts, the quality of search in a bug tracking system is crucial. However, all existing search functions in a bug tracking system produce results with undesired relevance and ranking. Hence, it is essential to provide an effective search function to any bug tracking system.Learning to rank (LTR) is a supervised machine learning technique that is used to construct a ranking model from training data. We propose a novel approach by using LTR to search for potentially related bug reports in a bug tracking system. Our method uses a set of proposed features of bug reports and queries. A preliminary evaluation shows that our approach can enhance the quality of searching for similar bug reports, therefore, relieving the burden of developers in dealing with duplicate bug reports.

For a large and complex software system, the project team could receive a large number of bug reports. Some bug reports could be duplicates as they essentially report the same problem. It is often tedious and costly to manually check if a newly reported bug is a duplicate of an already reported bug. In this paper, we propose BugSim, a method that can automatically retrieve duplicate bug reports given a new bug report. BugSim is based on learning to rank concepts. We identify textual and statistical features of bug reports and propose a similarity function for bug reports based on the features. We then construct a training set by assembling pairs of duplicate and non-duplicate bug reports. We train the weights of features by applying the stochastic gradient descent algorithm over the training set. For a new bug report, we retrieve candidate duplicate reports using the trained model. We evaluate BugSim using more than 45,100 real bug reports of twelve Eclipse projects. The evaluation results show that the proposed method is effective. On average, the recall rate for the top 10 retrieved reports is 76.11%. Furthermore, BugSim outperforms the previous state-of-art methods that are implemented using SVM and BM25Fext.

With a great number of software applications that have been developed, software maintenance has become an important and challenging task, particularly due to the increasing scale of software projects. Even if developers can create and update bug reports in bug repositories to support software maintenance, a large software project receives a large number of bug reports each day. For reducing the workload of developers, many researchers and software engineers have begun recommending appropriate developers to fix bugs. This process is called bug triage and is a hot research topic for software maintenance. In this paper, we propose a hybrid bug triage algorithm, combining a probability model and an experience model to rank all candidate developers for fixing a new bug. For this study, we adopted the smoothed Unigram Model (UM) instead of the traditional Vector Space Model (VSM) to search similar bug reports. In the probability model, we used a social network to analyze the probability of fixing a new bug for a candidate developer. We first proposed to add a new feature (the number of re-opened bugs) in order to get the fixing probability. In the experience model, we considered the number of fixed bugs and fixing cost for each candidate developer as the estimate factor. In addition, we introduced a new concept, activity factor, to better model developers' experience. We performed the experiments on two large-scale, open source projects. The results show that our method can effectively recommend the best developer for fixing bugs.

With the use of increasingly complex software, software bugs are inevitable. Software developers rely on bug reports to identify and fix these issues. In this process, developers inspect suspected buggy source code files, relying heavily on a bug report. This process is often time-consuming and increases the cost of software maintenance. To resolve this problem, we propose a novel bug localization method using topic-based similar commit information. First, the method determines similar topics for a given bug report. Then, it extracts similar bug reports and similar commit information for these topics. To extract similar bug reports on a topic, a similarity measure is calculated for a given bug report. In the process, for a given bug report and source code, features shared by similar source codes are classified and extracted; combining these features improves the method’s performance. The extracted features are presented to the convolutional neural network’s long short-term memory algorithm for model training. Finally, when a bug report is submitted to the model, a suspected buggy source code file is detected and recommended. To evaluate the performance of our method, a baseline performance comparison was conducted using code from open-source projects. Our method exhibits good performance.

Bug reports are widely employed to facilitate software tasks in software maintenance. Since bug reports are contributed by people, the authorship characteristics of contributors may heavily impact the performance of resolving software tasks. Poorly written bug reports may delay developers when fixing bugs. However, no in-depth investigation has been conducted over the authorship characteristics. In this study, we first leverage byte-level $N$-grams to model the authorship characteristics and employ Normalized Simplified Profile Intersection (NSPI) to identify the similarity of the authorship characteristics. Then, we investigate a series of properties related to contributors authorship characteristics, including the evolvement over time and the variation among distinct products in open source projects. Moreover, we show how to leverage the authorship characteristics to facilitate a well-known task in software maintenance, namely Bug Report Summarization (BRS). Experiments on open source projects validate that incorporating the authorship characteristics can effectively improve a state-of-the-art method in BRS. Our findings suggest that contributors should retain stable authorship characteristics and the authorship characteristics can assist in resolving software tasks.

Open-source software projects are characterized by their loose management property. Most of the activities of their developers are voluntary instead of mandatory. Compared to closed-source software projects, open-source projects are less dependent on external turbulence, but more on its own structure and operation mechanism. In this paper, we assume that the activities of open-source software projects are only dependent on time. We use time series analysis techniques to study the time dependence of open-source software activities. The activities of open-source Software projects are extracted from mailing lists, bug reports, and revision history. Three mailing list (Linux, FreeBSD, and Apache HTTP), two bug archives (Eclipse and Apache Software Foundation), and one revision history (Apache Software Foundation) are mined. Various time series analysis techniques are used. We find that some activities of some open-source projects are cyclic and seasonally dependent, some are cyclic but seasonally independent, and some are acyclic. We build regression models for cyclic activities and analyzed their model accuracy.

With the increasing number of software bugs, bug fixing plays an important role in software development and maintenance. To improve the efficiency of bug resolution, developers utilize bug reports to resolve given bugs. Especially, bug triagers usually depend on bugs' descriptions to suggest priority levels for reported bugs. However, manual priority assignment is a time-consuming and cumbersome task. To resolve this problem, recent studies have proposed many approaches to automatically predict the priority levels for the reported bugs. Unfortunately, these approaches still face two challenges that include words' nonconsecutive semantics in bug reports and the imbalanced data. In this article, we propose a novel approach that graph convolutional networks (GCN) based on weighted loss function to perform the priority prediction for bug reports. For the first challenge, we build a heterogeneous text graph for bug reports and apply GCN to extract words' semantics in bug reports. For the second challenge, we construct a weighted loss function in the training phase. We conduct the priority prediction on four open-source projects, including Mozilla, Eclipse, Netbeans, and GNU compiler collection. Experimental results show that our method outperforms two baseline approaches in terms of the F-measure by weighted average of 13.22%.

Bug reporting is essentially an uncoordinated process. The same bugs could be repeatedly reported because users or testers are unaware of previously reported bugs. As a result, extra time could be spent on bug triaging and fixing. In order to reduce redundant effort, it is important to provide bug reporters with the ability to search for previously reported bugs. The search functions provided by the existing bug tracking systems are using relatively simple ranking functions, which often produce unsatisfactory results. In this paper, we adopt Ranking SVM, a Learning to Rank technique to construct a ranking model for effective bug report search. We also propose to use the knowledge of Wikipedia to discover the semantic relations among words and documents. Given a user query, the constructed ranking model can search for relevant bug reports in a bug tracking system. Unlike related works on duplicate bug report detection, our approach retrieves existing bug reports based on short user queries, before the complete bug report is submitted. We perform evaluations on more than 16,340 Eclipse and Mozilla bug reports. The evaluation results show that the proposed approach can achieve better search results than the existing search functions provided by Bugzilla and Lucene. We believe our work can help users and testers locate potential relevant bug reports more precisely.

Software bug reports are important project artifacts that evolve throughout the life of a software project. Software bugs are issues that are reported by users when these issues hinder their work. Software projects evolve over time as bugs are addressed and new features are added. Managing bugs can be a significant challenge as a project manager generally needs to be aware of all the bug reports for the current version, and this can be even more challenging when the number of bug reports becomes large. It is preferable that a developer new to a project improves her knowledge with the project along with the bug reports during working on it, which is likely to help her avoid or handle the reported issues. In this paper, we propose a prototype that assists developers review a project's bug reports by interactively visualizing insightful information regarding the bug reports using topic analysis. In addition, in order to reduce developers' time and efforts when studying a bug report, the proposed prototype also provides an extractive summary visualization of each bug report. In this research, it is shown that our proposed prototype performs better in terms of precision, recall, and F-measure than a baseline approach that uses time-sensitive keyword extraction.

Bug localisation is a core program comprehension task in software maintenance: given the observation of a bug, where is it located in the source code files? Information retrieval (IR) approaches see a bug report as the query, and the source code files as the documents to be retrieved, ranked by relevance. Such approaches have the advantage of not requiring expensive static or dynamic analysis of the code. However, most of state-of-the-art IR approaches rely on project history, in particular previously fixed bugs and previous versions of the source code. We present a novel approach that directly scores each current file against the given report, thus not requiring past code and reports. The scoring is based on heuristics identified through manual inspection of a small set of bug reports. We compare our approach to five others, using their own five metrics on their own six open source projects. Out of 30 performance indicators, we improve 28. For example, on average we find one or more affected files in the top 10 ranked files for 77% of the bug reports. These results show the applicability of our approach to software projects without history.

Recent years have witnessed the growing demands for resolving numerous bug reports in software maintenance. Aiming to reduce the time testers/developers take in perusing bug reports, the task of bug report summarization has attracted a lot of research efforts in the literature. However, no systematic analysis has been conducted on attribute construction, which heavily impacts the performance of supervised algorithms for bug report summarization. In this study, we first conduct a survey to reveal the existing methods for attribute construction in mining software repositories. Then, we propose a new method named Crowd-Attribute to infer new effective attributes from the crowd-generated data in crowdsourcing and develop a new tool named Crowdsourcing Software Engineering Platform to facilitate this method. With Crowd-Attribute, we successfully construct 11 new attributes and propose a new supervised algorithm named Logistic Regression with Crowdsourced Attributes (LRCA). To evaluate the effectiveness of LRCA, we build a series of large scale datasets with 105 177 bug reports. Experiments over both the public dataset SDS with 36 manually annotated bug reports and new large-scale datasets demonstrate that LRCA can consistently outperform the state-of-the-art algorithms for bug report summarization.