Faculty Profiles - OHIRA Masao

Published Papers - OHIRA Masao

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A Release-Aware Bug Triaging Method Considering Developers' Bug-Fixing Loads

Yutaro Kashiwa, Masao Ohira

IEICE TRANSACTIONS ON INFORMATION AND SYSTEMS ( IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG ) E103D ( 2 ) 348 - 362 2020.02 [Refereed]

This paper proposes a release-aware bug triaging method that aims to increase the number of bugs that developers can fix by the next release date during open-source software development. A variety of methods have been proposed for recommending appropriate developers for particular bug-fixing tasks, but since these approaches only consider the developers' ability to fix the bug, they tend to assign many of the bugs to a small number of the project's developers. Since projects generally have a release schedule, even excellent developers cannot fix all the bugs that are assigned to them by the existing methods. The proposed method places an upper limit on the number of tasks which are assigned to each developer during a given period, in addition to considering the ability of developers. Our method regards the bug assignment problem as a multiple knapsack problem, finding the best combination of bugs and developers. The best combination is one that maximizes the efficiency of the project, while meeting the constraint where it can only assign as many bugs as the developers can fix during a given period. We conduct the case study, applying our method to bug reports from Mozilla Firefox, Eclipse Platform and GNU compiler collection (GCC). We find that our method has the following properties: (1) it can prevent the bug-fixing load from being concentrated on a small number of developers; (2) compared with the existing methods, the proposed method can assign a more appropriate amount of bugs that each developer can fix by the next release date; (3) it can reduce the time taken to fix bugs by 35%-41%, compared with manual bug triaging;

Hierarchical Clustering of OSS License Statements toward Automatic Generation of License Rules.

Yunosuke Higashi, Masao Ohira, Yutaro Kashiwa, Yuki Manabe 0001

JIP 27 ( 1 ) 42 - 50 2019 [Refereed]

Reusing open source software (OSS) components for one's own software products has become common in the modern software development. Automated license identification tools have been proposed to help developers identify OSS licenses, since a large number of licenses sometimes must be checked before attempting to reuse. Of the existing tools, Ninka[1] can most correctly identify licenses of each source file by using regular expressions. In case Ninka does not have license identification rules for unknown licenses, Ninka reports these as "unknown licenses" which must be checked by developers manually. Since completely-new or derived OSS licenses appear nearly every year, a license identification tool should be appropriately maintained by adding regular expressions corresponding to the new licenses. The final goal of our study is to construct a method to automatically create candidate license rules to be added to a license identification tool such as Ninka. Toward achieving the goal, files identified as unknown licenses must be classified by license firstly. In this paper, we propose a hierarchical clustering which divides unknown licenses into clusters of files with a single license. We conduct a case study to confirm the usefulness of our clustering method when it is applied for classifying 2,801, 1,230 and 2,446 unknown license statement files for Linux Kernel v4.4.6, FreeBSD v10.3.0 and Debian v7.8.0 respectively. As a result, it is confirmed that our method can create clusters which are suitable as candidates for generating license rules automatically.------------------------------This is a preprint of an article intended for publication Journal ofInformation Processing(JIP). This preprint should not be cited. Thisarticle should be cited as: Journal of Information Processing Vol.27(2019) (online)DOI http://dx.doi.org/10.2197/ipsjjip.27.42------------------------------Reusing open source software (OSS) components for one's own software products has become common in the modern software development. Automated license identification tools have been proposed to help developers identify OSS licenses, since a large number of licenses sometimes must be checked before attempting to reuse. Of the existing tools, Ninka[1] can most correctly identify licenses of each source file by using regular expressions. In case Ninka does not have license identification rules for unknown licenses, Ninka reports these as "unknown licenses" which must be checked by developers manually. Since completely-new or derived OSS licenses appear nearly every year, a license identification tool should be appropriately maintained by adding regular expressions corresponding to the new licenses. The final goal of our study is to construct a method to automatically create candidate license rules to be added to a license identification tool such as Ninka. Toward achieving the goal, files identified as unknown licenses must be classified by license firstly. In this paper, we propose a hierarchical clustering which divides unknown licenses into clusters of files with a single license. We conduct a case study to confirm the usefulness of our clustering method when it is applied for classifying 2,801, 1,230 and 2,446 unknown license statement files for Linux Kernel v4.4.6, FreeBSD v10.3.0 and Debian v7.8.0 respectively. As a result, it is confirmed that our method can create clusters which are suitable as candidates for generating license rules automatically.------------------------------This is a preprint of an article intended for publication Journal ofInformation Processing(JIP). This preprint should not be cited. Thisarticle should be cited as: Journal of Information Processing Vol.27(2019) (online)DOI http://dx.doi.org/10.2197/ipsjjip.27.42------------------------------

A Bug Triaging Method for Reducing the Time to Fix Bugs in Large-scale Open Source Software Development

柏祐太郎, 大平雅雄, 阿萬裕久, 亀井靖高

情報処理学会論文誌ジャーナル(Web) ( Information Processing Society of Japan (IPSJ) ) 56 ( 2 ) 669-681 (WEB ONLY) - 681 2015.02 [Refereed]

This paper proposes a bug triaging method to reduce the time to fix bugs in large-scale open source software development. Our method considers the upper limit of tasks which can be fixed by a developer in a certain period. In this paper, we conduct a case study of applying our method to Mozilla Firefox and Eclipse Platform projects and show the following findings: (1) using our method mitigates the situation where the majority of bug-fixing tasks are assigned to particular developers, (2) our method can reduce up to 50%-83% of time to fix bugs compared with the manual bug triaging method and up to 34%-38% compared with the existing method, and (3) the two factors, Preference (adequate for fixing a bug) and Limit (limits of developers' working hours), used in our method have an dispersion effect on the task assignment.

A Data Mining Method for Understanding Co-evolution of OSS Systems and Communities

山谷陽亮, 大平雅雄, PHANNACHITTA Passakorn, 伊原彰紀

情報処理学会論文誌ジャーナル(Web) ( Information Processing Society of Japan (IPSJ) ) 56 ( 1 ) 59-71 (WEB ONLY) - 71 2015.01 [Refereed]

While using open source software (OSS) has been becoming common as a means for developing software systems, many companies still have a reluctance to utilize OSS products. This paper proposes a data mining method to analyze the co-evolution process of OSS systems and communities quantitatively. The method includes time-delayed correlation analysis to investigate whether changes in the amount of an explanatory variable have an impact on changes in the amount of an objective variable after a certain period of time. Through a case study of the Eclipse Platform project using 131 software metrics and our method, we found that our method extracted 31 correlations which cannot be extracted by the common correlation analysis. We also found that our method can support additional analyses to observe the co-evolution process in the Eclipse Platform project more precisely.

Studying re-opened bugs in open source software

Emad Shihab, Akinori Ihara, Yasutaka Kamei, Walid M. Ibrahim, Masao Ohira, Bram Adams, Ahmed E. Hassan, Ken-ichi Matsumoto

EMPIRICAL SOFTWARE ENGINEERING ( SPRINGER ) 18 ( 5 ) 1005 - 1042 2013.10 [Refereed]

Bug fixing accounts for a large amount of the software maintenance resources. Generally, bugs are reported, fixed, verified and closed. However, in some cases bugs have to be re-opened. Re-opened bugs increase maintenance costs, degrade the overall user-perceived quality of the software and lead to unnecessary rework by busy practitioners. In this paper, we study and predict re-opened bugs through a case study on three large open source projects-namely Eclipse, Apache and OpenOffice. We structure our study along four dimensions: (1) the work habits dimension (e.g., the weekday on which the bug was initially closed), (2) the bug report dimension (e.g., the component in which the bug was found) (3) the bug fix dimension (e.g., the amount of time it took to perform the initial fix) and (4) the team dimension (e.g., the experience of the bug fixer). We build decision trees using the aforementioned factors that aim to predict re-opened bugs. We perform top node analysis to determine which factors are the most important indicators of whether or not a bug will be re-opened. Our study shows that the comment text and last status of the bug when it is initially closed are the most important factors related to whether or not a bug will be re-opened. Using a combination of these dimensions, we can build explainable prediction models that can achieve a precision between 52.1-78.6 % and a recall in the range of 70.5-94.1 % when predicting whether a bug will be re-opened. We find that the factors that best indicate which bugs might be re-opened vary based on the project. The comment text is the most important factor for the Eclipse and OpenOffice projects, while the last status is the most important one for Apache. These factors should be closely examined in order to reduce maintenance cost due to re-opened bugs.

Designing a System for Real-Time Software Development Management

大平雅雄, 横森励士, 阪井誠, 岩村聡, 小野英治, 新海平, 横川智教（Part： Lead author )

電子情報通信学会論文誌 D-1 ( The Institute of Electronics, Information and Communication Engineers ) J88-D-1 ( 2 ) 228 - 239 2005.02 [Refereed]

本研究は, 信頼性や生産性に課題の多いソフトウェア開発の分野において, 科学的根拠に基づく開発手法である実証的ソフトウェア工学(Empirical Software Engineering)の確立を目指すEASE(Empirical Approach to Software Engineering)プロジェクトの一環として行われたものである.本論文では, より実践的なプロセス改善の支援を目的として構築したシステム, EPM(Empirical Project Monitor)について述べる.EPMは, 現在広く普及している開発支援フリーウェア(CVS, Mailman, GNATS等)と連携することによって開発履歴データをリアルタイムに収集し, 定量的データ分析を可能にするシステムである.EPMを利用したソフトウェア開発では, 管理者及び開発者は常時, プロジェクトの進捗状況や作業状況を客観的に把握することが可能となる.その効用として, プロジェクトの問題点を迅速に発見し的確なプロジェクト管理が行いやすくなるため, 効果的なプロセス改善活動の実施を期待することができる.システムの有用性を検証するために, 試作したEPMを現行のEPM開発プロジェクトに適用した結果, 開発者に大きな作業負荷を与えることなく当該プロジェクトの状況を分析することができた.

Building an Issue Classification Model on Technical Debt

Yuta Kimura, Masao Ohira （Part： Last author,　Corresponding author )

IPSJ Journal 64 ( 1 ) 2 - 12 2023.01 [Refereed]

Automating License Rule Generation to Help Maintain Rule-based OSS License Identification Tools

Yunosuke Higashi, Masao Ohira, Yuki Manabe

Journal of Information Processing ( Information Processing Society of Japan ) 31 2 - 12 2023.01 [Refereed]

OSSプロジェクトへのオンボーディング支援のためのGood First Issue自動分類

堀口日向, 大平雅雄

コンピュータソフトウェア 39 ( 4 ) 31 - 37 2022.10 [Refereed]

A Preliminary Analysis of Gpl Related License Violations in Docker Images

Yunosuke Higashi, Yutaro Kashiwa, Masao Ohira （Part： Last author )

Proceedings of 2022 IEEE International Conference on Software Analysis, Evolution and Reengineering (SANER '22) 433 - 437 2022.03 [Refereed]

単語分散表現による類義語統一と単語N-gramによるフレーズ抽出に基づくセキュリティ要件分類手法

宮崎智己, 東裕之輔, 大平雅雄（Part： Last author )

情報処理学会論文誌 63 ( 1 ) 94 - 103 2022.03 [Refereed]

Onboarding to Open Source Projects with Good First Issues: A Preliminary Analysis

Hyuga Horiguchi, Itsuki Omori, Masao Ohira （Part： Last author,　Corresponding author )

2021 IEEE International Conference on Software Analysis, Evolution and Reengineering (SANER) ( IEEE ) 501 - 505 2021.03 [Refereed]

Report on the 26th foundation of software engineering workshop (fose2019)

Shuji Morisaki, Masao Ohira, Akito Monden

Computer Software ( Japan Society for Software Science and Technology ) 37 ( 4 ) 3 - 9 2020.10

A bot for suggesting questions that match each user's expertise.

Katsunori Fukui, Tomoki Miyazaki, Masao Ohira

2019 IEEE/ACM 1st International Workshop on Bots in Software Engineering (BotSE) ( IEEE / ACM ) 18 - 19 2019.05 [Refereed]

Suggesting Questions that Match Each User's Expertise in Community Question and Answering Services

Katsunori Fukui, Tomoki Miyazaki, Masao Ohira

2019 20TH IEEE/ACIS INTERNATIONAL CONFERENCE ON SOFTWARE ENGINEERING, ARTIFICIAL INTELLIGENCE, NETWORKING AND PARALLEL/DISTRIBUTED COMPUTING (SNPD) ( IEEE ) 513 - 518 2019 [Refereed]

Stack Overflow has been already recognized as an indispensable CQA (Community Question and Answering) service for developers. However developers as questioners sometimes cannot get any answers or they only can get incomplete answers to resolve their questions, since over several thousands of questions and answers are posted on a daily basis and expert developers are currently facing with a difficulty in finding questions which can be better or best answered by them. In order address the issue, our study aims at developing a bot that helps expert developers find questions matching each developer's expertise. The existing study [8] proposed a promising approach to the expert recommendation for CQA services, based on PMF (Probabilistic Matrix Factorization) algorithm. In order to improve the accuracy of the expert recommendation, in this paper we present our approach which combines the PMF (Probabilistic Matrix Factorization) approach and a term expansion techniques using word embeddings. As a result of an experiment comparing our approach with the existing approach only based on PMF, we show that our approach based on PMF and the term expansion with Word2vec and fastText slightly outperforms the existing approach only based on PMF.

Code Clone Tracer (CCT): A Tracking Tool for Analyzing Human and Social Factors in Creating and Reusing Code Clones

Yusuke Kukita, Kojiro Noguchi, Masao Ohira

2019 20TH IEEE/ACIS INTERNATIONAL CONFERENCE ON SOFTWARE ENGINEERING, ARTIFICIAL INTELLIGENCE, NETWORKING AND PARALLEL/DISTRIBUTED COMPUTING (SNPD) ( IEEE ) 519 - 524 2019 [Refereed]

This paper introduces a tool called CCT (Code Clone Tracer) which is designed to help practitioners and researchers analyze the impacts of human/social factors on software quality in creating and reusing code clones. CCT tracks a history of created and reused code clones for all the revisions in a distributed version control system such as Git. The tool also has features to analyze the relationship between bug-inducing changes and developers, working together with a bug tracking system such as Bugzilla and JIRA. This paper reports our pilot case study where CCT is applied to three open source projects (RxJava, c:geo, and Jackson databind). The results of the case study indicated that a small number of particular developers were involved in many of clone changes to resolve issues.

What Are the Perception Gaps Between FLOSS Developers and SE Researchers? A Case of Bug Finding Research

Yutaro Kashiwa, Akinori Ihara, Masao Ohira

OPEN SOURCE SYSTEMS, OSS 2019 ( SPRINGER INTERNATIONAL PUBLISHING AG ) 556 44 - 57 2019 [Refereed]

In recent years, many researchers in the SE community have been devoting considerable efforts to provide FLOSS developers with a means to quickly find and fix various kinds of bugs in FLOSS products such as security and performance bugs. However, it is not exactly sure how FLOSS developers think about bugs to be removed preferentially. Without a full understanding of FLOSS developers' perceptions of bug finding and fixing, researchers' efforts might remain far away from FLOSS developers' needs. In this study, we interview 322 notable GitHub developers about high impact bugs to understand FLOSS developers' needs for bug finding and fixing, and we manually inspect and classify developers' answers (bugs) by symptoms and root causes of bugs. As a result, we show that security and breakage bugs are highly crucial for FLOSS developers. We also identify what kinds of high impact bugs should be studied newly by the SE community to help FLOSS developers.

An Politeness Analysis for Understanding Continuous Activities of Developers in OSS Communities

宮崎智己, 伊原彰紀, 大平雅雄, 東裕之輔, 山谷陽亮

情報処理学会論文誌ジャーナル(Web) 59 ( 1 ) 2‐11 (WEB ONLY) 2018.01 [Refereed]

ソフトウェアテストにおける静的解析ツールの段階的適用による不具合修正工数の更なる低減 ―民生用音響・映像機器向け組み込みソフトウェア開発へのQACの段階的適用とその実証評価―

鶴田雅明, 大平雅雄, 門田暁人, 松本健一

情報社会学会誌 11 ( 1 ) 5 - 16 2016 [Refereed]

Open Source Software Engineering.

伊原彰紀, 大平雅雄

コンピュータソフトウェア ( Japan Society for Software Science and Technology ) 33 ( 1 ) 28‐40(J‐STAGE) - 1_27 2016 [Refereed] [Invited]

Clustering OSS License Statements Toward Automatic Generation of License Rules

Yunosuke Higashi, Yuki Manabe, Masao Ohira

PROCEEDINGS 7TH INTERNATIONAL WORKSHOP ON EMPIRICAL SOFTWARE ENGINEERING IN PRACTICE (IWESEP 2016) ( IEEE ) 30 - 35 2016 [Refereed]

Reusing open source software (OSS) components for own software products has become common in the modern software development. Automated license identification tools has been proposed to help developers identify OSS licenses, since a large number of licenses sometimes must be checked to be reused. Of the existing tools, Ninka [1] can most correctly identify licenses of each source file by using regular expressions. In case Ninka does not have license identification rules for unknown licenses, Ninka reports they are "unknown licenses" which must be checked by developers manually. Since completely new or derived OSS licenses appear nearly every year, a license identification tool should be appropriately maintained by adding regular expressions corresponding to the new licenses. The final goal of our study is to construct a method to automatically create candidates of license rules to be added to a license identification tool such as Ninka. Toward achieving the goal, files identified as unknown licenses must be classified by license firstly. In this paper, we propose a hierarchical clustering which divides unknown licenses into clusters of files with a single license. We conduct a case study to confirm the usefulness of our clustering method when it is applied for classifying 2,838 unknown license files of Debian v7.8.0. As a result, it is confirmed that our method can create clusters which are suitable as candidates for generating license rules automatically.

A Case Study on the Misclassification of Software Performance Issues in an Issue Tracking System

Masao Ohira, Hayato Yoshiyuki, Yosuke Yamatani

2016 IEEE/ACIS 15TH INTERNATIONAL CONFERENCE ON COMPUTER AND INFORMATION SCIENCE (ICIS) ( IEEE COMPUTER SOC ) 855 - 860 2016 [Refereed]

In this study we focus on the misclassification of issue reports regarding software performance in OSS development. IEEE Std 610 [1] defines performance as "The degree to which a system or component accomplishes its designated functions within given constraints, such as speed, accuracy, or memory usage." The definition implies that there is no rigorous criteria nor quantitative measure to detect a software performance problem, but rather it relies on a subjective judgement. OSS users sometimes mistakenly report a performance bug as a request for improving software performance and sometimes mistakenly report an improvement request for fixing a performance bug. The misclassification of report types can impedes the efficient bug-fix process in OSS development, since OSS developers preferentially spend time fixing bugs which might be improvement requests (i.e., not bugs) in reality. In this paper we strengthen our previous study for the Apache Wicket project by manually inspecting 1,000 bugs and 1,000 improvement requests respectively to more precisely understand the impacts of the misclassification on the bug-fix process in OSS development.

機械学習を用いたテキスト分類によるライセンス特定のためのルール作成プロセス支援

東裕之輔, 眞鍋雄貴, 大平雅雄

ソフトウェア・シンポジウム 2015 in 和歌山 70 - 79 2015.06 [Refereed]

A Dataset of High Impact Bugs: Manually-Classified Issue Reports

Masao Ohira, Yutaro Kashiwa, Yosuke Yamatani, Hayato Yoshiyuki, Yoshiya Maeda, Nachai Limsettho, Keisuke Fujino, Hideaki Hata, Akinori Ihara, Kenichi Matsumoto

12TH WORKING CONFERENCE ON MINING SOFTWARE REPOSITORIES (MSR 2015) ( IEEE ) 518 - 521 2015 [Refereed]

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).

Predicting Bug-Fix Time Using Social Relationships between Assignors and Assignees in OSS Development

吉行勇人, 大平雅雄, 戸田航史

コンピュータソフトウェア ( Japan Society for Software Science and Technology ) 32 ( 2 ) 2.128-2.134 (J-STAGE) - 2_134 2015 [Refereed]

A large number of bugs are reported to a large-scale open source software (OSS) project. Since it is very difficult to fix all the bugs, a manager in the project needs to know time to fix bugs to decide which bugs should be fixed before the next release. In this paper we focus on social relationships between assignors and assignees and construct prediction models based on a random forest method and logistic regression, in order to predict the time to fix bugs. As a result of our experiment, we show that our model predicts more accurately whether a bug is fixed within a day or not, compared with the existing prediction model.

ソフトウェア品質の第三者評価における探索的データ解析ツールの利用とその効果:OSSデータを対象とした検証実験

大平雅雄, 伊原彰紀, 中野大輔, 松本健一（Part： Lead author )

SEC Journal ( 情報処理推進機構技術本部ソフトウェア・エンジニアリング・センター ) 10 ( 1 ) 24 - 31 2014.03 [Refereed]

Adaptive Search Framework: Better Search Result for Community

Papon Yongpisanpop, Masao Ohira, Akinori Ihara, Kenichi Matsumoto

情報社会学会誌 8 ( 2 ) 29 - 43 2014.03 [Refereed]

An Exploratory Analysis for Studying Software Evolution: Time-Delayed Correlation Analysis

Yosuke Yamatani, Masao Ohira

2014 6TH INTERNATIONAL WORKSHOP ON EMPIRICAL SOFTWARE ENGINEERING IN PRACTICE (IWESEP 2014) ( IEEE ) 13 - 18 2014 [Refereed]

We propose an exploratory analysis method for software repositories so that you can study software evolution without an explicit goal. The method extends the traditional correlation analysis to consider a time lag between any pair of metrics. Using data collected from three kinds of repositories, the method automatically calculates optimal parameters to deal with a time lag between metrics and returns the highest correlation coeffcient for each pair of metrics. Our case study using one hundred metrics data from three OSS projects shows that the method allows us to find unexpected relationships in some pairs of metrics if we only use the traditional correlation analysis and that using such relationships can be used to build an analysis goal to understand software evolution.

Early Identification of Future Committers in Open Source Software Projects

Akinori Ihara, Yasutaka Kamei, Masao Ohira, Ahmed E. Hassan, Naoyasu Ubayashi, Ken-ichi Matsumoto

2014 14TH INTERNATIONAL CONFERENCE ON QUALITY SOFTWARE (QSIC 2014) ( IEEE COMPUTER SOC ) 47 - 56 2014 [Refereed]

There exists two types of developers in Open Source Software (OSS) projects: 1) Committers who have permission to commit edited source code to the Version Control System (VCS), 2) Developers who contribute source code but cannot commit to the VCS directly. In order to develop and evolve high quality OSS, projects are always in search of new committers. OSS projects often promote strong developers to become committers. When existing committers find strong developers, they propose their promotion to a committer role. Delaying the committer-promotion might lead to strong developers departing from an OSS project and the project losing them. However early committer-promotion comes with its own slew of risks as well (e.g., the promotion of inexperienced developers). Hence, committer-promotion decisions are critical for the quality and successful evolution of OSS projects. In this paper, we examine the committer-promotion phenomena for two OSS projects (Eclipse and Firefox). We find that the amount of activities by future committers was higher than the amount of activities by developers who did not become committers). We also find that some developers are promoted to a committer role very rapidly (within a few month) while some of developers take over one year to become a committer. Finally, we develop a committer-identification model to assist OSS projects identifying future committers.

A Pilot Study of Diversity in High Impact Bugs

Yutaro Kashiwa, Hayato Yoshiyuki, Yusuke Kukita, Masao Ohira

2014 IEEE INTERNATIONAL CONFERENCE ON SOFTWARE MAINTENANCE AND EVOLUTION (ICSME) ( IEEE COMPUTER SOC ) 536 - 540 2014 [Refereed]

Since increasing complexity and scale of modern software products imposes tight scheduling and resource allocations on software development projects, a project manager must carefully triage bugs to determine which bug should be necessarily fixed before shipping. 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 report our pilot study on high impact bugs, which classifies bugs reported to four open source projects into six types of high impact bugs.

Predicting the Bug Fixing Time Based on the Bug Assignment Patterns in OSS Development

正木仁, 大平雅雄, 伊原彰紀, 松本健一

情報処理学会論文誌ジャーナル(CD-ROM) 54 ( 2 ) 933 - 944 2013.02 [Refereed]

Predicting the Bug Fixing Time Based on the Bug Assignment Patterns in OSS Development

正木仁, 大平雅雄, 伊原彰紀, 松本健一

情報処理学会論文誌 ( 情報処理学会 ) 54 ( 2 ) 933 - 944 2013.02 [Refereed]

大規模OSSプロジェクトには日々大量の不具合が報告されており，不具合修正時間（OSSプロジェクトに報告された不具合が解決するまでに要する時間）をより正確に見積もることが重要になってきている．OSSプロジェクト管理者は，次期バージョンのリリースまでにどの不具合を修正すべきかを判断しなければならないためである．しかしながら，不具合の修正範囲の大きさや問題の複雑さの違い，ボランティアを主体とする開発者のスキルセットの違いなどの要因によって，個々の不具合の修正時間を見積もることは容易ではない．そのため近年，OSS開発における不具合修正時間の予測に関する研究がさかんに行われている．本論文では，不具合割当てパターンを用いて不具合修正時間の予測モデルを構築する．不具合割当てパターンとは，不具合修正タスク割当て時の不具合報告者・管理者・修正担当者の3者の社会的関係を分類したものである．不具合割当てパターンの違いにより，修正作業にとりかかるまでの時間および修正作業自体に要する時間はそれぞれ大きく異なることが知られている．従来研究の多くは不具合情報（重要度や優先度など）に基づいて予測モデルを構築しているが，不具合管理パターンを考慮することでさらなる予測精度の向上を期待できる．本論文では，Eclipse PlatformおよびJDTを対象として構築した予測モデルの評価を行った．実験の結果，不具合割当てパターンが不具合修正時間の予測精度向上に寄与するとともに，指定期間内（1週間以内など）に不具合修正が完了するか否かの判断を支援できることが分かった．さらに，本予測モデルを利用することで，Platformで約16%，JDTで約10%多くの不具合を修正可能と判断できることが分かった．The number of reported bugs has been increasing especially in large-scale open source software (OSS) projects. Project managers in the projects have to decide which bugs should be resolved until they release the next version of their products. However it is not easy to estimate the time to resolve each bug due to the differences of the size of required modifications, the difficulty of each modification, skill set of each developer, and so forth. To address this issue, many studies have tried to predict the bug fixing time in OSS development. In this paper we constructs a prediction model for the bug fixing time, using the bug assignment patterns which have an impact on developer's performance of fixing bugs. The bug assignment patterns categorize the social relationships among bug reporters, managers, and developers in assigning bug fixing tasks. While most studies in the past only used the information extracted from bug reports itself, taking the bug assignment patterns into account would lead to prediction results with higher accuracy. Using data from the Eclipse Platform and JDT projects, we evaluates the prediction model. As a result, we found that the bug assignment patterns improved the prediction accuracy and help OSS managers make sure if a target bug will be resolved in a specified period (e.g., one week). We also found that our prediction model can contribute to resolve more bugs until the specified release (about 16% in Platform and about 10% in JDT).

A new perspective on the socialness in bug triaging: A case study of the eclipse platform project

Masao Ohira, Hayato Yoshiyuki

2013 5th International Workshop on Social Software Engineering, SSE 2013 - Proceedings 29 - 32 2013 [Refereed]

This paper explores how social relationships among developers impact on the efficiency of bug fixes. From the case study of the Eclipse Platform project, we found that (1) past achievements of bug triaging by particular pairs of assignors and fixers do not necessarily impact on the time to fix bugs, (2) rather, the time required to fix a bug can depend on who assigns the bug fixing task to a fixer. These findings would imply that we need to not only consider who should fix this bug? but also take into account a fixer's perspective who should assign this bug? or who should ask to whom?, in order to better support the bug triaging process. Copyright 2013 ACM.

An Algorithm for Gradual Patch Acceptance Detection in Open Source Software Repository Mining

Passakorn Phannachitta, Akinori Ihara, Pijak Jirapiwong, Masao Ohira, Ken-ichi Matsumoto

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES ( IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG ) E95A ( 9 ) 1478 - 1489 2012.09 [Refereed]

Nowadays, software development societies have given more precedence to Open Source Software (OSS). There is much research aimed at understanding the OSS society to sustain the OSS product. To lead an OSS project to a successful conclusion, researchers study how developers change source codes called patches in project repositories. In existing studies, we found an argument in the conventional patch acceptance detection procedure. It was so simplified that it omitted important cases from the analysis, and would lead researchers to wrong conclusions. In this research, we propose an algorithm to overcome the problem. To prove out our algorithm, we constructed a framework and conducted two case studies. As a result, we came to a new and interesting understanding of patch activities.

Good or Bad Committers? - A Case Study of Committer's Activities on the Eclipse's Bug Fixing Process

Anakorn Jongyindee, Masao Ohira, Akinori Ihara, Ken-ichi Matsumoto

IEICE TRANSACTIONS ON INFORMATION AND SYSTEMS ( IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG ) E95D ( 9 ) 2202 - 2210 2012.09 [Refereed]

There are many roles to play in the bug fixing process in open source software development. A developer called "Committer", who has a permission to submit a patch into a software repository, plays a major role in this process and holds a key to the successfulness of the project. Despite the importance of committer's activities, we suspect that sometimes committers can make mistakes which have some consequences to the bug fixing process (e.g., reopened bugs after bug fixing). Our research focuses on studying the consequences of each committer's activities to this process. We collected each committer's historical data from the Eclipse-Platform's bug tracking system and version control system and evaluated their activities using bug status in the bug tracking system and commit log in the version control system. Then we looked deeper into each committer's characteristics to see the reasons why some committers tend to make mistakes more than the others.

OSS開発における不具合修正プロセスの現状と課題:不具合修正時間の短縮化へ向けた分析

伊原彰紀, 大平雅雄, 松本健一

情報社会学会誌 6 ( 2 ) 5 - 16 2012.03 [Refereed]

A Candidate Committer Prediction Based on Developer Activities in Open Source Software Projects

伊原彰紀, 亀井靖高, 大平雅雄, 松本健一, 鵜林尚靖

( 電子情報通信学会 ) 2012.02

本論文では，オープンソースソフトウェア（OSS）プロジェクトに参加する一般開発者の中からコミッターに推薦されるべき有能な開発者（コミッター候補者）を見つけ出すことを目的とする．近年，数百件もの不具合がプロジェクトに日々，報告されている現状から，コミッターへの過度な負担が原因となり不具合修正の長期化を招いている．コミッターの負担を軽減させるためにコミッターを増員するという手段があるが，プロジェクトに参加する一般開発者の中からコミッター候補者を見つけることは容易ではない．本論文では，コミッター候補者を見つけ出すために既存コミッターの過去の活動とその活動量を分析し，コミッター予測モデルを構築した．モデル構築には，コミッター候補者と一般開発者の活動（パッチの投稿，パッチの検証，開発に伴う議論）履歴とプロジェクトでの活動期間を用いた．分析の結果，継続的にパッチの投稿，パッチの検証を行う開発者がコミッターに昇格していることが分かった．また，構築したコミッター予測モデルは，ランダムに予測する場合に比べて予測精度が5～7倍高いことが分かった．

A Candidate Committer Prediction Based on Developer Activities in Open Source Software Projects

IHARA Akinori, KAMEI Yasutaka, OHIRA Masao, MATSUMOTO Ken-ichi, UBAYASHI Naoyasu

The IEICE transactions on information and systems (Japanese edetion) ( The Institute of Electronics, Information and Communication Engineers ) 95 ( 2 ) 237 - 249 2012.02

本論文では,オープンソースソフトウェア(OSS)プロジェクトに参加する一般開発者の中からコミッターに推薦されるべき有能な開発者(コミッター候補者)を見つけ出すことを目的とする.近年,数百件もの不具合がプロジェクトに日々,報告されている現状から,コミッターへの過度な負担が原因となり不具合修正の長期化を招いている.コミッターの負担を軽減させるためにコミッターを増員するという手段があるが,プロジェクトに参加する一般開発者の中からコミッター候補者を見つけることは容易ではない.本論文では,コミッター候補者を見つけ出すために既存コミッターの過去の活動とその活動量を分析し,コミッター予測モデルを構築した.モデル構築には,コミッター候補者と一般開発者の活動(パッチの投稿,パッチの検証,開発に伴う議論)履歴とプロジェクトでの活動期間を用いた.分析の結果,継続的にパッチの投稿,パッチの検証を行う開発者がコミッターに昇格していることが分かった.また,構築したコミッター予測モデルは,ランダムに予測する場合に比べて予測精度が5〜7倍高いことが分かった.

Lessons Learned from Collaborative Research in Software Engineering: A Student's Perspective.

Anakorn Jongyindee, Pattara Leelaprute, Masao Ohira, Ken-ichi Matsumoto

13th ACIS International Conference on Software Engineering, Artificial Intelligence, Networking and Parallel/Distributed Computing, SNPD 2012, Kyoto, Japan, August 8-10, 2012 ( IEEE Computer Society ) 494 - 497 2012 [Refereed]

The Impact of Bug Management Patterns on Bug Fixing: A Case Study of Eclipse Projects

Masao Ohira, Ahmed E. Hassan, Naoya Osawa, Ken-ichi Matsumoto

2012 28TH IEEE INTERNATIONAL CONFERENCE ON SOFTWARE MAINTENANCE (ICSM) ( IEEE ) 264 - 273 2012 [Refereed]

An efficient bug management process is critical for the success of software projects. Prior work has focused on improving this process, for example, by automating bug triaging, detecting duplicate bugs, and understanding the rationale for re-opening bugs. This paper continues this line of work by exploring the people who are involved in the bug management process. In particular we develop four patterns that distill the different relations between the people involved in the process: the reporter, triager, and fixer of a bug. Through a case study on the Eclipse Platform and JDT projects, we demonstrate that these patterns have an impact on the efficiency of the bug management process. For example, we find that using our patterns project personnel can improve their efficiency through better communication about bugs before assigning them.

An Investigation on Software Bug-Fix Prediction for Open Source Software Projects-A Case Study on the Eclipse Project

Akinori Ihara, Yasutaka Kamei, Akito Monden, Masao Ohira, Jacky Wai Keung, Naoyasu Ubayashi, Ken-ichi Matsumoto

2012 19TH ASIA-PACIFIC SOFTWARE ENGINEERING CONFERENCE WORKSHOPS (APSECW), VOL. 2 ( IEEE COMPUTER SOC ) 112 - 119 2012 [Refereed]

Open source software projects (OSS) receive a large number of bug reports from various contributors and developers alike, where many planned to be fixed by OSS developers. Given the next release cycle information, OSS users can be more effective and flexible in planning and to fix the bugs that are not to be fixed in the next release. It is therefore vital for OSS users to learn which bugs the OSS developers will fix, unfortunately such information may not be readily available, nor there is a prediction framework exists to serve such an important purpose. In this study, we would like to answer the question "Will this bug be fixed by the next release?", this is addressed by building a bug fixing prediction model based on the characteristics of a bug-related metric and by incorporating the progress of bug fixing measures such as status, period and developer metrics to provide aggregated information for the OSS users. The proposed model calculates the deviance of each variable to analyze the most important metrics, and it has been experimented using a case study with Eclipse platform. Result shows a bug fixing prediction model using both base metrics and state metrics provide significantly better performance in precision (139%) and recall (114%) than the standard model using only base metrics.

Good or Bad Committers? - A Case Study of Committer's Activities on the Eclipse's Bug Fixing Process.

Anakorn Jongyindee, Masao Ohira, Akinori Ihara, Ken-ichi Matsumoto

IEICE Trans. Inf. Syst. ( IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG ) 95-D ( 9 ) 2202 - 2210 2012 [Refereed]

There are many roles to play in the bug fixing process in open source software development. A developer called "Committer", who has a permission to submit a patch into a software repository, plays a major role in this process and holds a key to the successfulness of the project. Despite the importance of committer's activities, we suspect that sometimes committers can make mistakes which have some consequences to the bug fixing process (e.g., reopened bugs after bug fixing). Our research focuses on studying the consequences of each committer's activities to this process. We collected each committer's historical data from the Eclipse-Platform's bug tracking system and version control system and evaluated their activities using bug status in the bug tracking system and commit log in the version control system. Then we looked deeper into each committer's characteristics to see the reasons why some committers tend to make mistakes more than the others.

A System for Information Integration between Development Support Systems

Soichiro Tani, Akinori Ihara, Masao Ohira, Hidetake Uwano, Ken-ichi Matsumoto

3rd International Workshop on Empirical Software Engineering in Practice (IWESEP) 2011.11 [Refereed]

グローバル環境下におけるOSS開発者の情報交換に対する時差の影響

亀井靖高, 大平雅雄, 伊原彰紀, 小山貴和子, 松本真佑, 松本健一, 鵜林尚靖

情報社会学会学会誌 6 ( 2 ) 13 - 30 2011.11 [Refereed]

ソフトウェア開発における知識コラボレーション

大平雅雄, YE Yunwen, 中小路久美代, 山本恭裕

人工知能学会誌 ( 人工知能学会 ) 26 ( 1 ) 66 - 78 2011.01 [Refereed] [Invited]

Effects of a Synchronized Scoring Interface on Musical Quality.

Yuji Takai, Masao Ohira, Ken-ichi Matsumoto

Online Communities and Social Computing - 4th International Conference, OCSC 2011, Held as Part of HCI International 2011, Orlando, FL, USA, July 9-14, 2011. Proceedings ( Springer ) 363 - 372 2011 [Refereed]

A Quantitative Evaluation on the Software Use Experience with Electroencephalogram

Hitoshi Masaki, Masao Ohira, Hidetake Uwano, Ken-ichi Matsumoto

DESIGN, USER EXPERIENCE, AND USABILITY: THEORY, METHODS, TOOLS AND PRACTICE, PT 2 ( SPRINGER-VERLAG BERLIN ) 6770 469 - 477 2011 [Refereed]

In usability testing, experimenters need to perform a pre-training, so as to control software-use experiences of subjects. The pre-training in usability testing is very important because subjects' software-use experiences have a large effect on a result of a subjective evaluation of software. This paper aims to evaluate the software-use experiences quantitatively using EEG. We have conducted experiments to observe the relationships between subjects' software-use experiences and EEG in using software. As a result, we found that there was a significant difference between them.

An analysis of gradual patch application: A better explanation of patch acceptance

Passakorn Phannachitta, Pijak Jirapiwongy, Akinori Ihara, Masao Ohira, Ken-Ichi Matsumoto

Proceedings - Joint Conference of the 21st International Workshop on Software Measurement, IWSM 2011 and the 6th International Conference on Software Process and Product Measurement, MENSURA 2011 ( IEEE Computer Society ) 106 - 115 2011 [Refereed]

Patch submission has been known as one of the most important activities to sustain the open source software (OSS). The patch archive can be analyzed to procure many benefit cognizance for supporting the OSS project works. The recent models and methods that analyze the patches acceptance are quite rack of comprehensive
hence, complex activities such as a committer portioning the submitted patch out and accept are still excluded from the analysis. Therefore, the results derived from those methods would be inadequate to conclude the actual patch acceptance. In this research, we introduce an algorithm for analyzing patch acceptance including the partial and gradually accepted conditions. Validating our algorithm, we present our methods for indicating the partial and gradual application of the submitted patch between either mailing list and SVN or Bugzilla and CVS which are the commonly deployed patchactivities related system. We studied on two well known OSS projects
Apache HTTP and Eclipse Platform. We obtained a fascinating conclusion that larger patches have more confident to be accepted than the smaller contradicted to other analysis that came from the recent methods. © 2011 IEEE.

Good or bad committers? A case study of committers' cautiousness and the consequences on the bug fixing process in the eclipse project

Anakorn Jongyindee, Masao Ohira, Akinori Ihara, Ken-Ichi Matsumoto

Proceedings - Joint Conference of the 21st International Workshop on Software Measurement, IWSM 2011 and the 6th International Conference on Software Process and Product Measurement, MENSURA 2011 ( IEEE Computer Society ) 116 - 125 2011 [Refereed]

There are many roles to play in the bug fixing process in open source software development. A developer called "Committer", who has a permission to submit a patch into software repository, plays a major role in this process and hold a key to the successfulness of the project. In this work, we have observed each committer activities from the Eclipse-Platform bug tracking system and version archives. Despite the importance of committer's activities, we suspected that sometimes committers can make mistakes, which have negative consequences to the bug fixing process. Our research focus on studying the consequences of each committer's activities to this process. We collected each committer's historical data and evaluated each of them by comparing the more cautiousness to less cautiousness committers. Then we looked deeper into each committer's characteristics to see the reasons why some committers tend to make mistakes more than the others. From our results, we would like to make a humbly suggestion to the OSS's committers to be aware of their importance to the projects and be cautious before doing their jobs. © 2011 IEEE.

CICRO: An Interactive Visual Interface for Crowd Communication Online.

Masao Ohira, Hitoshi Masaki, Ken-ichi Matsumoto

Online Communities and Social Computing - 4th International Conference, OCSC 2011, Held as Part of HCI International 2011, Orlando, FL, USA, July 9-14, 2011. Proceedings ( Springer ) 251 - 260 2011 [Refereed]

Community search: A collaborative searching web application with a user ranking system

Papon Yongpisanpop, Masao Ohira, Ken-Ichi Matsumoto

Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) ( Springer ) 6778 378 - 386 2011 [Refereed]

People are using search engine in daily life. But most of the tools that we have today treat information-seeking tasks as a transient activity. In this research paper we introduce a web application system that provides collaborative function and experts finding system. We develop a system that will help user to organize search result and to do the collaboration with others. With the new iterative algorithm, users will also gain more percentage of needed result and the system will be able to suggest the experts related to the search keyword. © 2011 Springer-Verlag.

ライトユーザを対象としたオンライン協調作曲支援システム

大平雅雄, 木村昌樹, 松本健一

ヒューマンインタフェース学会論文誌 12 ( 3 ) 21 - 31 2010.08 [Refereed]

A Time-Lag Analysis for Improving Communication among OSS Developers

Masao Ohira, Kiwako Koyama, Akinori Ihara, Shinsuke Matsumoto, Yasutaka Kamei, Ken-ichi Matsumoto

NEW FRONTIERS IN ARTIFICIAL INTELLIGENCE ( SPRINGER-VERLAG BERLIN ) 6284 135 - 146 2010 [Refereed]

In the open source software (OSS) development environment, a communication time-lag among developers is more likely to happen due to time differences among locations of developers and differences of working hours for OSS development. A means for effective communication among OSS developers has been increasingly demanded in recent years, since an OSS product and its users requires a prompt response to issues such as defects and security vulnerabilities. In this paper, we propose an analysis method for observing the time-lag of communication among developers in an OSS project and then facilitating the communication.

3rd International Workshop on Supporting Knowledge Collaboration in Software Development (KCSD2009)

Masao Ohira, Yunwen Ye

Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) 6284 89 - 90 2010 [Refereed]

The creation of modern software systems requires knowledge from a wide range of domains: application domains, computer hardware and operating systems, algorithms, programming languages, vast amount of component libraries, development environments, the history of the software system, and users. Because few software developers have all the required knowledge, the development of software has to rely on distributed cognition by reaching into a complex networked world of information and computer mediated collaboration. The success of software development, therefore, hinges on how various stakeholders are able to share and combine their knowledge through cooperation, collaboration and co-construction. © 2010 Springer-Verlag.

Predicting re-opened bugs: A case study on the Eclipse project

Emad Shihab, Akinori Ihara, Yasutaka Kamei, Walid M. Ibrahim, Masao Ohira, Bram Adams, Ahmed E. Hassan, Ken-Ichi Matsumoto

Proceedings - Working Conference on Reverse Engineering, WCRE ( IEEE Computer Society ) 249 - 258 2010 [Refereed]

Bug fixing accounts for a large amount of the software maintenance resources. Generally, bugs are reported, fixed, verified and closed. However, in some cases bugs have to be re-opened. Re-opened bugs increase maintenance costs, degrade the overall user-perceived quality of the software and lead to unnecessary rework by busy practitioners. In this paper, we study and predict re-opened bugs through a case study on the Eclipse project. We structure our study along 4 dimensions: 1) the work habits dimension (e.g., the weekday on which the bug was initially closed on), 2) the bug report dimension (e.g., the component in which the bug was found) 3) the bug fix dimension (e.g., the amount of time it took to perform the initial fix) and 4) the team dimension (e.g., the experience of the bug fixer). Our case study on the Eclipse Platform 3.0 project shows that the comment and description text, the time it took to fix the bug, and the component the bug was found in are the most important factors in determining whether a bug will be re-opened. Based on these dimensions we create decision trees that predict whether a bug will be re-opened after its closure. Using a combination of our dimensions, we can build explainable prediction models that can achieve 62.9% precision and 84.5% recall when predicting whether a bug will be re-opened. © 2010 IEEE.

A Time-Lag Analysis Toward Improving the Efficiency of Communications among OSS Developers

Masao Ohira, Kiwako Koyama, Akinori Ihara, Shinsuke Matsumoto, Yasutaka Kamei, Ken-ichi Matsumoto

In Proceedings of The 3rd International Workshop on Knowledge Collaboration in Software Development (KCSD2009) 49 - 62 2009.11 [Refereed]

Temporal Changes of the Openness of An Oss Community: A Case Study of the Apache Http Server Community

Mizuki Yamamoto, Masao Ohira, Yasutaka Kamei, Shinsuke Matsumoto, Ken-ichi Matsumoto

In The 4th International Conference on Collaboration Technologies 2009 (CollabTech2009) 64 - 65 2009.08 [Refereed]

Q&Aコミュニティを対象とした回答の信頼性指標構築に向けた分析

瀧寛文, 森崎修司, 大平雅雄, 松本健一

情報社会学会誌 4 ( 1 ) 49 - 58 2009.06 [Refereed]

OSSコミュニティにおけるオープンコラボレーションの理解

松本真佑, 亀井靖高, 大平雅雄, 松本健一

情報社会学会学会誌 3 ( 2 ) 29 - 42 2009.03 [Refereed]

Webjig: An Automated User Data Collection System for Website Usability Evaluation

Mikio Kiura, Masao Ohira, Ken-ichi Matsumoto

HUMAN-COMPUTER INTERACTION, PT I ( SPRINGER-VERLAG BERLIN ) 5610 277 - 286 2009 [Refereed]

In order to improve website usability, it is important for developers to understand how users access websites. In this paper, we present Webjig, which is a Support system for website usability evaluation in order to resolve the problems associated with the existing systems. Webjig can collect users' interaction data from static and dynamic websites. Moreover, by using Webjig, developers can precisely identify users' activities on websites. By performing an experiment to evaluate the usefulness of Webjig, we have confirmed that developers could effectively improve website usability.

An Analysis Method for Improving a Bug Modification Process in Open Source Software Development

Akinori Ihara, Masao Ohira, Ken-ichi Matsumoto

IWPSE-EVOL 09: ERCIM WORKSHOP ON SOFTWARE EVOLUTION (EVOL) AND INTERNATIONAL WORKSHOP ON PRINCIPLES OF SOFTWARE EVOLUTION (IWPSE) ( ASSOC COMPUTING MACHINERY ) 135 - 143 2009 [Refereed]

As open source software products have evolved over time to satisfy a variety of demands from increasing users, they have become large and complex in general. Open source developers often face with challenges in fixing a considerable amount of bugs which are reported into a bug tracking system on a daily basis. As a result, he mean time to resolve bugs has been protracted in these days. In order to reduce the mean time to resolve bugs, managers/leaders of open source projects need to identify and understand the bottleneck of a bug modification process in their own projects. In this paper, we propose an analysis method which represents a bug modification process using a bug tracking system as a state transition diagram and then calculates the amount of time required to transit between states. We have conducted a case study using Firefox and Apache project data to confirm the usefulness of the analysis method. From the results of the case study, we have found that the method helped to reveal that both of the projects took a lot of time to verify results of bug modifications by developers.

Toward Constructing an Electroencephalogram Measurement Method for Usability Evaluation

Masaki Kimura, Hidetake Uwano, Masao Ohira, Ken-ichi Matsumoto

HUMAN-COMPUTER INTERACTION, PT I ( SPRINGER-VERLAG BERLIN ) 5610 95 - 104 2009 [Refereed]

This paper describes our pilot study toward constructing an electroencephalogram (EEG) measurement method for usability evaluation. The measurement method consists of two steps: (1) measuring EEGs of subjects for several tens of seconds after events or tasks that are targets to evaluate, and (2) analyzing how much components of the alpha and/or beta rhythm are contained in the measured EEGs. However, there only exists an empirical rule on measurement time length of EEGs for usability evaluation. In this paper, we conduct an experiment to reveal the optimal time length of EEGs for usability evaluation by analyzing changes of EEGs over time. From the results of the experiments, we have found that the time length Suitable for usability evaluation was more than 0 similar to 56.32 seconds.

An Analysis of Eye Movements during Browsing Multiple Search Results Pages

Yuko Matsuda, Hidetake Uwano, Masao Ohira, Ken-ichi Matsumoto

HUMAN-COMPUTER INTERACTION, PT I ( SPRINGER-VERLAG BERLIN ) 5610 121 - 130 2009 [Refereed]

In general, most search engines display a certain number of search results on a search results page at one time, separating the entire search results into multiple search results pages. Therefore, lower ranked results (e.g., 11th-ranked result) may be displayed on the top area of the next (second) page and might be more likely to be browsed by users, rather than results displayed on the bottom of the previous (first) results page. To better understand users' activities in web search, it is necessary to analyze the effect of display positions of search results while browsing multiple search results pages. In this paper, we present the results Of Our analysis of users' eye movements. We have conducted an experiment to measure eye movements during web search and analyzed how long users spend to view each search result. From the analysis results, we have found that search results displayed on the top of the latter page were viewed for a longer time than those displayed on the bottom of the former page.

脳波を利用したソフトウェアユーザビリティの評価―異なるバージョン間における周波数成分の比較

上野秀剛, 石田響子, 松田侑子, 福嶋祥太, 中道上, 大平雅雄, 松本健一, 岡田保紀

ヒューマンインタフェース学会論文誌 ( ヒュ-マンインタフェ-ス学会 ) 10 ( 2 ) 233 - 242 2008.05 [Refereed]

A Comparison Study on the Coordination between Developers and Users in Foss Communities

Shinsuke Matsumoto, Yasutaka Kamei, Masao Ohira, Ken-ichi Matsumoto

In Socio-Technical Congruence (STC2008) CD-ROM 1 - 9 2008.05 [Refereed]

Analysis of coordination between developers and users in the Apache community

Yasutaka Kamei, Shinsuke Matsumoto, Hirotaka Maeshima, Yoji Onishi, Masao Ohira, Ken-ichi Matsumoto

OPEN SOURCE DEVELOPMENT, COMMUNITIES AND QUALITY ( SPRINGER ) 275 81 - 92 2008 [Refereed]

Coordination is one of the keys for the success of open source software (OSS) communities because geographically distributed members need to collaborate on their work using communication tools (e.g., mailing lists, bulletin board systems, bug tracking systems, and so oil). In this paper, we investigated the informal social structure among developers and users by analyzing two mailing lists of developers and users in the Apache community based on betweenness centrality, one centrality measure proposed by Freeman. From the analysis results, we found that (1) participants with high betweenness coordinated activities between developers and users and (2) some participants have been functioning as coordinators in the community for a long time.

異分野コラボレーションとしてのソフトウェア要求抽出の支援

逵明憲, 大平雅雄, 森崎修司, 松本健一

電子情報通信学会論文誌 D ( The Institute of Electronics, Information and Communication Engineers ) J90-D ( 12 ) 3151 - 3160 2007.12 [Refereed]

ソフトウェア開発の初期工程であるソフトウェア要求抽出では,ステークホルダ(本論文では,顧客と要求分析者)間の背景知識や専門知識が異なるため,コミュニケーションが困難になる場合が多い.その結果,あいまいな要求が抽出されたり,顧客自身が気づいていない潜在的な要求の抽出に失敗するという問題が生じる.本研究は,ソフトウェア要求抽出を顧客と要求分析者の異分野コラボレーションとしてとらえ,顧客と要求分析者とのコミュニケーションを支援することにより,要求の明確化と顕在化を促進させるための方法を構築することを目的としている.本論文では,異分野協調作業支援環境EVIDII (an Environment for VIsualizing Differences of Individual Impressions)を要求抽出会議へ適用した実験について述べる.実験の結果,EVIDIIを用いた要求抽出会議は,インタビュー形式で行う従来の要求抽出会議に比べて,必須要求及び潜在的要求の抽出の点で優れていることが分かった.

Social Network Analysis on Communications for Knowledge Collaboration in Oss Communities

Takeshi Kakimoto, Yasutaka Kamei, Masao Ohira, Ken-ichi Matsumoto

In Proceedings of the 2nd International Workshop on Supporting Knowledge Collaboration in Software Development 35 - 41 2006.09 [Refereed]

A wearable interface for visualizing coauthor networks toward building a sustainable research community

Susumu Kuriyama, Masao Ohira, Hiroshi Igaki, Ken-Ichi Matsumoto

Proceedings of the Workshop on Advanced Visual Interfaces ( ACM Press ) 2006 492 - 495 2006 [Refereed]

In this paper, we introduce SCACS, a Social Context-Aware Communication System that facilitates face-to-face communications between old-timers and newcomers in a research community. SCACS provides users with information on coauthor relationships collocutors have in order to help users understand collocutors' research background and relations to own. While the system works so as to help newcomers get better understandings on the research community by meeting old-timers - central to the community, it also works to recruit newcomers who might bring new ideas and research topics, in order to make the community sustainable. One of the contributions of the paper is to show an example of a fusion of social networking and ubiquitous computing technologies, which have attracted a considerable amount of attentions in the last few years. In contrast to exploiting social interactions in real world to enhance experiences of social networking services in virtual world, SCACS collects information on social networks (e.g., coauthor relationships networks) from virtual spaces (that is, databases), and then visualizes them to facilitate face-to-face communications among people in physical environments through using wearable interfaces. Instead of providing users with complex social network graphs, SCACS transforms network graphs into tree maps so that users are able to better understand the community. Copyright 2004 ACM.

An electroencephalography experiment for evaluating impressions in browsing web pages

FUKUSHIMA Shota, NAKAMICHI Noboru, OKADA Yasunori, OHIRA Masao, SAKAI Makoto, SHIMA Kazuyuki, MATSUMOTO Ken-ichi

JES Ergonomics ( Japan Ergonomics Society ) 41 248 - 249 2005

Supporting knowledge collaboration using social networks in a large-scale online community of software development projects

M Ohira, T Ohoka, T Kakimoto, N Ohsugi, K Matsumoto

12TH ASIA-PACIFIC SOFTWARE ENGINEERING CONFERENCE, PROCEEDINGS ( IEEE COMPUTER SOC ) 835 - 840 2005 [Refereed]

The scale-free network shown in the small world phenomenon indicates that our human society consists of a small number of people who play the role of hubs linked with many nodes (persons) and a large number of people as nodes linked with few nodes. From our analysis of a large-scale online community-SourceForge.net which has a large number of developers and projects, we have found that SourceForge also exists as a scale-free network. That is, only a minority of developers join many projects and have rich links with other developers, while the majority join few projects and have very limited social relations with others. The goal of our study is to build a system that supports knowledge collaboration in a large-scale online community of software development projects. In this paper, we discuss the challenges of supporting knowledge collaboration in such a large online community that is a scale-free network and then introduce the prototype system called D-SNS (Dynamic Social Networking System).

Accelerating cross-project knowledge collaboration using collaborative filtering and social networks.

Masao Ohira, Naoki Ohsugi, Tetsuya Ohoka, Ken-ichi Matsumoto

Proceedings of the 2005 International Workshop on Mining Software Repositories, MSR 2005, Saint Louis, Missouri, USA, May 17, 2005 ( ACM ) 2005 [Refereed]

Accelerating cross-project knowledge collaboration using collaborative filtering and social networks.

Masao Ohira, Naoki Ohsugi, Tetsuya Ohoka, Ken-ichi Matsumoto

ACM SIGSOFT Software Engineering Notes 30 ( 4 ) 1 - 5 2005 [Refereed]

Empirical Project Monitor: A Tool for Mining Multiple Project Data.

Masao Ohira, Reishi Yokomori, Makoto Sakai, Ken-ichi Matsumoto, Katsuro Inoue, Koji Torii

Proceedings of the 1st International Workshop on Mining Software Repositories, MSR@ICSE 2004, Edinburgh, Scotland, UK, 25th May 2004 42 - 46 2004 [Refereed]

少人数実践プロジェクトにおける協調学習支援環境L‐EVIDIIの提案

大平雅雄, 中小路久美代, 蔵川圭, 山本恭裕（Part： Lead author )

教育システム情報学会誌 ( 教育システム情報学会事務局 ) 18 ( 3/4 ) 328 - 339 2001.11 [Refereed]

EVIDII: an environment to help externalizing implicit ideas through visualizing individual associations

M Ohira

HUMAN-COMPUTER INTERACTION - INTERACT'01 ( I O S PRESS ) 648 - 651 2001 [Refereed]

The goal of this study is to construct a shared communicative environment for supporting collaborative design that helps participants externalize their implicit ideas and gradually increase mutual understanding among them. The EVIDII (an Environment for VIsualizing Differences of Individual Impressions) system is an interactive tool that visualizes differences of individual associations between two data sets on multiple two-dimensional spaces. In this paper, I take web page design activities as one of collaborative design and describe the importance of externalizing implicit ideas for communications among stakeholders in the activities. This paper examines whether the approach that visualizes individual associations and exploits the role of "breakdowns" is useful to support the activities, and identifies challenges to support web page design activities by using EVIDII. I describe new challenges in order to support actual web page design activities by using EVIDII.

Computational support for collective creativity

K Nakakoji, Y Yamamoto, M Ohira

KNOWLEDGE-BASED SYSTEMS ( ELSEVIER SCIENCE BV ) 13 ( 7-8 ) 451 - 458 2000.12 [Refereed]

The goal of our research is to develop computer systems that support designers' collective creativity; such systems support individual creative aspects in design through the use of representations created by others in the community. We have developed two systems, IAM-eMMa and EVIDII, that both aim at supporting designers in finding visual images that would be useful for their creative design task. IAM-eMMa uses knowledge-based rules, which are constructed by other designers, to retrieve images related to a design task, and infers the underlying "rationale" when a designer chooses one of the images. EVIDII allows designers to associate affective words and images, and then shows several visual representations of the relationships among designers, images and words. By observing designers interacting with the two systems, we have identified that systems for supporting collective creativity need to be based on design knowledge that: (1) is contextualized; (2) is respectable and trustful; and (3) enables "appropriation" of a design task. (C) 2000 Elsevier Science B.V. All rights reserved.

EVIDII : A System that Supports Mutual Understanding through Visualizing Differences of Individual Impressions

OHIRA Masao, YAMAMOTO Yasuhiro, KURAKAWA Kei, NAKAKOJI Kumiyo （Part： Lead author )

Transactions of Information Processing Society of Japan ( 一般社団法人情報処理学会 ) 41 ( 10 ) 2814 - 2826 2000.10 [Refereed]

The goal of our research is to develop computational support to increase mutual understanding among participants of a group discussion(such as review meetings and focus groups)by using "breakdowns" to make them aware of implicit and tacit assumptions and background context of their externalized opinions. This paper first discusses the importance and the role of breakdowns in developing shared knowledge and mutual understanding. Then we describe our approach of using visualizations of differences of individual impressions to cause "breakdowns" during a group discussion. We have developed a prototype system called EVIDII(an Environment for VIsualizing Differences of Individual Impressions)based on the approach. EVIDII visualizes individuals' impressions of objects on multiple two-dimensional spaces. Users of EVIDII have been observed to gradually increase mutual understandig among them through interacting with EVIDII.

An Environment that Supports Understanding 'Differences' among People

M. Ohira, Y. Yamamoto, S. Takada, K. Nakakoji

2nd International Conference on Cognitive Science and the 16th Annual Meeting of the Japanese Cognitive Science Society Joint Conference 466-471 1999.07 [Refereed]

A framework that supports collective creativity in design using visual images.

Kumiyo Nakakoji, Yasuhiro Yamamoto, Masao Ohira

Proceedings of the 3rd Conference on Creativity & Cognition, Loughborough, United Kingdom, October 11-13, 1999 ( ACM ) 166 - 173 1999 [Refereed]

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