Published Papers - OHIRA Masao

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]

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]

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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.

DOI

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]

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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.

DOI

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]

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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.

DOI

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]

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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.

DOI

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]

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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.

DOI

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]

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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.

DOI

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

DOI

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]

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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).

DOI

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]

DOI

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]

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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]

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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.

DOI

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]

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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.