Ken-ichi Matsumoto

dblp:73/942 · also Kenichi Matsumoto · DBLP profile ↗
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12ranked-venue papers in the field
0as first author
8since 2021 · last 2026
ORCID · conflict

Domains — venue-derived; a paper can count in several

Other / Interdisciplinary · 10Knowledge Engineering, Semantic Web & Information Systems · 2
YearPublicationVenuePosition
2026 How AI Coding Agents Communicate: A Study of Pull Request Characteristics and Human Review Responses
abstract
The rapid adoption of large language models has led to the emergence of AI coding agents that autonomously create pull requests on GitHub. However, how these agents differ in their pull request description characteristics, and how human reviewers respond to them, remains underexplored. In this study, we conduct an empirical analysis of pull requests created by five AI coding agents using the AIDev dataset. We analyze agent differences in pull request description characteristics, including structural features, and examine human reviewer response in terms of review activity, response timing, sentiment, and merge outcomes. We find that AI coding agents exhibit distinct PR description styles, which are associated with differences in reviewer engagement, response time, and merge outcomes. We observe notable variation across agents in both reviewer interaction metrics and merge rates. These findings highlight the role of pull request presentation and reviewer interaction dynamics in human–AI collaborative software development.
Kan Watanabe, Rikuto Tsuchida, Takahiro Monno, Kazuma Yamasaki, Youmei Fan, Kazumasa Shimari, Ken-ichi Matsumoto
MSR8
2026 Who Writes the Docs in SE 3.0?: Agent vs. Human Documentation Pull Requests
abstract
As software engineering moves toward SE 3.0, AI agents are increasingly used to carry out development tasks and contribute changes to software projects. It is therefore important to understand the extent of these contributions and how human developers review and intervene, since these factors shape the risks of delegating work to AI agents. While recent studies have examined how AI agents support software development tasks (e.g., code generation, issue resolution, and PR automation), their role in documentation tasks remains underexplored–even though documentation is widely consumed and shapes how developers understand and use software.
Kazuma Yamasaki, Joseph Ayobami Joshua, Tasha Settewong, Mahmoud Alfadel, Kazumasa Shimari, Ken-ichi Matsumoto
MSR6
2026 Let's Make Every Pull Request Meaningful: An Empirical Analysis of Developer and Agentic Pull Requests
Haruhiko Yoshioka, Takahiro Monno, Haruka Tokumasu, Taiki Wakamatsu, Yuki Ota, Nimmi Weeraddana, Ken-ichi Matsumoto
MSR7
2025 Mining for Lags in Updating Critical Security Threats: A Case Study of Log4j Library
abstract
The Log4j-Core vulnerability, known as Log4Shell, exposed significant challenges to dependency management in software ecosystems. When a critical vulnerability is disclosed, it is imperative that dependent packages quickly adopt patched versions to mitigate risks. However, delays in applying these updates can leave client systems exposed to exploitation. Previous research has primarily focused on NPM, but there is a need for similar analysis in other ecosystems, such as Maven. Leveraging the 2025 mining challenge dataset of Java dependencies, we identify factors influencing update lags and categorize them based on version classification (major, minor, patch release cycles). Results show that lags exist, but projects with higher release cycle rates tend to address severe security issues more swiftly. In addition, over half of vulnerability fixes are implemented through patch updates, highlighting the critical role of incremental changes in maintaining software security. Our findings confirm that these lags also appear in the Maven ecosystem, even when migrating away from severe threats.
Hidetake Tanaka, Kazuma Yamasaki, Momoka Hirose, Takashi Nakano, Youmei Fan, Kazumasa Shimari, Raula Gaikovina Kula, Ken-ichi Matsumoto
MSR8
2025 Do Developers Depend on Deprecated Library Versions? A Mining Study of Log4j
abstract
Log4j has become a widely adopted logging library for Java programs due to its long history and high reliability. Its widespread use is notable not only because of its maturity but also due to the complexity and depth of its features, which have made it an essential tool for many developers. However, Log4j 1.x, which reached its end of support (deprecated), poses significant security risks and has numerous deprecated features that can be exploited by attackers. Despite this, some clients may still rely on this library. We aim to understand whether clients are still using Log4j 1.x despite its official support ending. We utilized the Mining Software Repositories 2025 challenge dataset, which provides a large and representative sample of open-source software projects. We analyzed over 10,000 log entries from the Mining Software Repositories 2025 challenge dataset using the Goblin framework to identify trends in usage rates for both Log4j 1.x and Log4j-core 2.x. Specifically, our study addressed two key issues: (1) We examined the usage rates and trends for these two libraries, highlighting any notable differences or patterns in their adoption. (2) We demonstrate that projects initiated after a deprecated library has reached the end of its support lifecycle can still maintain significant popularity. These findings highlight how deprecated are still popular, with the next step being to understand the reasoning behind these adoptions.
Haruhiko Yoshioka, Sila Lertbanjongngam, Masayuki Inaba, Youmei Fan, Takashi Nakano, Kazumasa Shimari, Raula Gaikovina Kula, Ken-ichi Matsumoto
MSR8
2024 DevGPT: Studying Developer-ChatGPT Conversations
abstract
This paper introduces DevGPT, a dataset curated to explore how software developers interact with ChatGPT, a prominent large language model (LLM). The dataset encompasses 29,778 prompts and responses from ChatGPT, including 19,106 code snippets, and is linked to corresponding software development artifacts such as source code, commits, issues, pull requests, discussions, and Hacker News threads. This comprehensive dataset is derived from shared ChatGPT conversations collected from GitHub and Hacker News, providing a rich resource for understanding the dynamics of developer interactions with ChatGPT, the nature of their inquiries, and the impact of these interactions on their work. DevGPT enables the study of developer queries, the effectiveness of ChatGPT in code generation and problem solving, and the broader implications of AI-assisted programming. By providing this dataset, the paper paves the way for novel research avenues in software engineering, particularly in understanding and improving the use of LLMs like ChatGPT by developers.
Tao Xiao 0001, Christoph Treude, Hideaki Hata, Ken-ichi Matsumoto
MSR4
2023 Intertwining Communities: Exploring Libraries that Cross Software Ecosystems
abstract
Using libraries in applications has helped developers reduce the costs of reinventing already existing code. However, an increase in diverse technology stacks and third-party library usage has led developers to inevitably switch technologies and search for similar libraries implemented in the new technology. To assist with searching for these replacement libraries, maintainers have started to release their libraries to multiple ecosystems. Our goal is to explore the extent to which these libraries are intertwined between ecosystems. We perform a large-scale empirical study of 1.1 million libraries from five different software ecosystems, i.e., PyPI, CRAN, Maven, RubyGems, and NPM, to identify 4,146 GitHub repositories. As a starting point, insights from the study raise implications for library maintainers, users, contributors, and researchers into understanding how these different ecosystems are becoming more intertwined with each other.
Kanchanok Kannee, Raula Gaikovina Kula, Supatsara Wattanakriengkrai, Ken-ichi Matsumoto
MSR4
2022 Using Bandit Algorithms for Selecting Feature Reduction Techniques in Software Defect Prediction
abstract
Background: Selecting a suitable feature reduction technique. when building a defect prediction model, can be challenging. Different techniques can result in the selection of different independent variables which have an impact on the overall performance of the prediction model. To help in the selection, previous studies have assessed the impact of each feature reduction technique using different datasets. However, there are many reduction techniques, and therefore some of the well-known techniques have not been assessed by those studies. Aim: The goal of the study is to select a high-accuracy reduction technique from several candidates without preliminary assessments. Method: We utilized bandit algorithm (BA) to help with the selection of best features reduction technique for a list of candidates. To select the best feature reduction technique, BA evaluates the prediction accuracy of the candidates, comparing testing results of different modules with their prediction results. By substituting the reduction technique for the prediction method, BA can then be used to select the best reduction technique. In the experiment, we evaluated the performance of BA to select suitable reduction technique. We performed cross version defect prediction using 14 datasets. As feature reduction techniques, we used two assessed and two non-assessed techniques. Results: Using BA, the prediction accuracy was higher or equivalent than existing approaches on average, compared with techniques selected based on an assessment. Conclusions: BA can have larger impact on improving prediction models by helping not only on selecting suitable models, but also in selecting suitable feature reduction techniques.
Masateru Tsunoda, Akito Monden, Koji Toda, Amjed Tahir, Kwabena Ebo Bennin, Keitaro Nakasai, Masataka Nagura, Ken-ichi Matsumoto
MSR8
2015 A Dataset of High Impact Bugs: Manually-Classified Issue Reports
abstract
The importance of supporting test and maintenance activities in software development has been increasing, since recent software systems have become large and complex. Although in the field of Mining Software Repositories (MSR) there are many promising approaches to predicting, localizing, and triaging bugs, most of them do not consider impacts of each bug on users and developers but rather treat all bugs with equal weighting, excepting a few studies on high impact bugs including security, performance, blocking, and so forth. To make MSR techniques more actionable and effective in practice, we need deeper understandings of high impact bugs. In this paper we introduced our dataset of high impact bugs which was created by manually reviewing four thousand issue reports in four open source projects (Ambari, Camel, Derby and Wicket).
Masao Ohira, Yutaro Kashiwa, Yosuke Yamatani, Hayato Yoshiyuki, Yoshiya Maeda, Nachai Limsettho, Keisuke Fujino, Hideaki Hata, Akinori Ihara, Ken-ichi Matsumoto
MSR10
2014 Kataribe: a hosting service of historage repositories
abstract
In the research of Mining Software Repositories, code repository is one of the core source since it contains the product of software development. Code repository stores the versions of files, and makes it possible to browse the histories of files, such as modification dates, authors, messages, etc. Although such rich information of file histories is easily available, extracting the histories of methods, which are elements of source code files, is not easy from general code repositories. To tackle this difficulty, we have developed Historage, a fine-grained version control system. Historage repository is a Git repository which is built upon original Git repository. Therefore, similar mining techniques for general Git repositories are applicable to Historage repositories. Kataribe is a hosting service of Historage repositories, which enables researchers and developers to browse method histories on the web and clone Historage repositories to local. The Kataribe project aims to maintain and expand the datasets and features.
Kenji Fujiwara, Hideaki Hata, Erina Makihara, Yusuke Fujihara, Naoki Nakayama, Hajimu Iida, Ken-ichi Matsumoto
MSR7
2008 Analyzing Factors of Defect Correction Effort in a Multi-Vendor Information System Development
abstract
This paper describes an empirical study to reveal factors influencing defect correction effort in software development. In the study we collected various attributes (metrics) of defects found in a typical medium-scale, multi-vendor information system development project in Japan over a six-month period. We then statistically analyzed the relationship between the defects' attributes and the correction effort. The analysis confirmed the well-known principle “defects are the more expensive the later they are detected” by revealing that defects detected in the “system test” were 4.88 times more expensive than those detected in the “coding/unit test”. Another principle “defects are more expensive the longer they survive in software” was also confirmed by revealing that defects, which survived two or more development phases, were 4.44 times more expensive than those detected immediately. We also identified other factors, such as defect reproducibility, severity, and the cause of detection delay, that had a significant influence on the correction effort.
Tomoko Matsumura, Shuji Morisaki, Akito Monden, Ken-ichi Matsumoto
J. Comput. Inf. Syst.4
2005 Software Analysis by Code Clones in Open Source Software
Shinji Uchida, Akito Monden, Naoki Ohsugi, Toshihiro Kamiya, Ken-ichi Matsumoto, Hideo Kudo
J. Comput. Inf. Syst.5