Free/Libre Open Source Software Projects Research Articles

Participation in community-based free/libre open source software development tasks: the impact of task characteristics

PurposeThis paper explores how task characteristics in terms of trigger type and task topic influence individual participation in community-based free/libre open source software (FLOSS) development by considering participation in individual tasks rather than entire projects.Design/methodology/approachA quantitative study was designed using choose tasks that were carried out via the email discourse on the developers' email fora in five FLOSS projects. Choice process episodes were selected as the unit of analysis and were coded for the task trigger and topic. The impact of these factors on participation (i.e. the numbers of participants and messages) was assessed by regression.FindingsThe results reveal differences in participation related to different task triggers and task topics. Further, the results suggest the mediating role of the number of participants in the relationships between task characteristics and the number of messages. The authors also speculate that project type serves as a boundary condition restricting the impacts of task characteristics on the number of participants and propose this relationship for future research.Research limitations/implicationsEmpirical support was provided to the important effects of different task characteristics on individual participation behaviors in FLOSS development tasks.Practical implicationsThe findings can help FLOSS participants understand participation patterns in different tasks and choose the types of tasks to attend to.Originality/valueThis research explores the impact of task characteristics on participation in FLOSS development at the task level, while prior research on participation in FLOSS development has focused mainly on factors at the individual and/or project levels.

On the prediction of long-lived bugs: An analysis and comparative study using FLOSS projects

Software evolution and maintenance activities in today’s Free/Libre Open Source Software (FLOSS) rely primarily on information extracted from bug reports registered in bug tracking systems. Many studies point out that most bugs that adversely affect the user’s experience across versions of FLOSS projects are long-lived bugs. However, proposed approaches that support bug fixing procedures do not consider the real-world lifecycle of a bug, in which bugs are often fixed very fast. This may lead to useless efforts to automate the bug management process. This study aims to confirm whether the number of long-lived bugs is significantly high in popular open-source projects and to characterize the population of long-lived bugs by considering the attributes of bug reports. We also aim to conduct a comparative study evaluating the prediction accuracy of five well-known machine learning algorithms and text mining techniques in the task of predicting long-lived bugs. We collected bug reports from six popular open-source projects repositories (Eclipse, Freedesktop, Gnome, GCC, Mozilla, and WineHQ) and used the following machine learning algorithms to predict long-lived bugs: K-Nearest Neighbor, Naïve Bayes, Neural Networks, Random Forest, and Support Vector Machines. Our results show that long-lived bugs are relatively frequent (varying from 7.2% to 40.7%) and have unique characteristics, confirming the need to study solutions to support bug fixing management. We found that the Neural Network classifier yielded the best results in comparison to the other algorithms evaluated. Research efforts regarding long-lived bugs are needed and our results demonstrate that it is possible to predict long-lived bugs with a high accuracy (around 70.7%) despite the use of simple prediction algorithms and text mining methods.

Roles and politeness behavior in community-based free/libre open source software development

Community-based Free/Libre Open Source Software (FLOSS) development relies on contributions from both core and peripheral members. Prior research on core–periphery has focused on software coding-related behaviors. We study how core–periphery roles are related to social-relational behavior in terms of politeness behavior. Data from two FLOSS projects suggest that both core and peripheral members use more positive politeness strategies than negative strategies. Further, core and peripheral members use different strategies to protect positive face in positive politeness, which we term respect and intimacy, respectively. Our results contribute to FLOSS research and politeness theory.

Stigmergic coordination in FLOSS development teams: Integrating explicit and implicit mechanisms

The vast majority of literature on coordination in team-based projects has drawn on a conceptual separation between explicit (e.g. plans, feedback) and implicit coordination mechanisms (e.g. mental maps, shared knowledge). This analytic distinction presents some limitations in explaining how coordination is reached in organizations characterized by distributed teams, scarce face to face meetings and fuzzy and changing lines of authority, as in free/libre open source software (FLOSS) development.Analyzing empirical illustrations from two FLOSS projects, we highlight the existence of a peculiar model, stigmergic coordination, which includes aspects of both implicit and explicit mechanisms. The work product itself (implicit) and the characteristics under which it is shared (explicit) play an under-appreciated role in helping software developers manage dependencies as they arise. We develop this argument beyond the existing literature by working with an existing coordination framework, considering the role that the codebase itself might play at each step. We also discuss the features and the practices to support stigmergic coordination in distributed teams, as well as recommendations for future research.

Understanding group maintenance behavior in Free/Libre Open-Source Software projects: The case of Fire and Gaim

In this paper, we investigate group maintenance behavior in community-based Free/Libre Open-Source Software (FLOSS) development teams. Adopting a sociolinguistic perspective, we conceptualize group maintenance behavior as interpersonal communication tactics—specifically, social presence and politeness tactics—that help maintain relationships among group members. Developer email messages were collected from two FLOSS projects with different development statuses, and their content was analyzed to identify frequently used group maintenance tactics. We then compared the group maintenance tactics used in the two projects, finding differences that reflect changes in the project work practices. Our work theoretically contributes to FLOSS research and has practical implications for FLOSS practitioners.

Enhancing software engineering education through open source projects: Four years of students’ perspectives

This paper presents the results after four years of running of an instructional method that utilizes free/libre open source software (FLOSS) projects as tools for teaching software engineering in formal education. In the last four academic years, a total of 408 juniors majoring in Informatics (in a 4-year program) participated in the study, assuming the roles of requirements engineers, testers, developers, and designers/analysts. Students appreciated the benefits gained by the method and identified aspects that require further improvement. In the paper, we present (a) the details of our method, (b) students' opinions as recorded through a questionnaire including both closed and open ended questions, and (c) conclusions on how the use of FLOSS projects can be applied, and be beneficial for the students.

Assessing the Open Source Development Processes Using OMM

The assessment of development practices in Free Libre Open Source Software (FLOSS) projects can contribute to the improvement of the development process by identifying poor practices and providing a list of necessary practices. Available assessment methods (e.g., Capability Maturity Model Integration (CMMI)) do not address sufficiently FLOSS-specific aspects (e.g., geographically distributed development, importance of the contributions, reputation of the project, etc.). We present a FLOSS-focused, CMMI-like assessment/improvement model: the QualiPSo Open Source Maturity Model (OMM). OMM focuses on the development process. This makes it different from existing assessment models that are focused on the assessment of the product. We have assessed six FLOSS projects using OMM. Three projects were started and led by a software company, and three are developed by three different FLOSS communities. We identified poorly addressed development activities as the number of commit/bug reports, the external contributions, and the risk management. The results showed that FLOSS projects led by companies adopt standard project management approaches as product planning, design definition, and testing, that are less often addressed by community led FLOSS projects. The OMM is valuable for both the FLOSS community, by identifying critical development activities necessary to be improved, and for potential users that can better decide which product to adopt.

Can Open Source projects succeed when the producers are not users? Lessons from the data processing field1

Free/Libre Open Source Software (FLOSS) proposes an original way to solve the incentive dilemma for the production of information goods, based on von Hippel (1988)’s user-as-innovator principle: as users benefit from innovation, they have incentive to produce it, and as they can expect cumulative innovation on their own proposition, they have incentive to share it. But what is the incentive for producers when they are not users? We discuss this question via a qualitative study of FLOSS projects in “algorithm-based industries”. We find that in this case producers hardly participate in such projects.

Effort estimation of FLOSS projects: a study of the Linux kernel

Empirical research on Free/Libre/Open Source Software (FLOSS) has shown that developers tend to cluster around two main roles: “core” contributors differ from “peripheral” developers in terms of a larger number of responsibilities and a higher productivity pattern. A further, cross-cutting characterization of developers could be achieved by associating developers with “time slots”, and different patterns of activity and effort could be associated to such slots. Such analysis, if replicated, could be used not only to compare different FLOSS communities, and to evaluate their stability and maturity, but also to determine within projects, how the effort is distributed in a given period, and to estimate future needs with respect to key points in the software life-cycle (e.g., major releases). This study analyses the activity patterns within the Linux kernel project, at first focusing on the overall distribution of effort and activity within weeks and days; then, dividing each day into three 8-hour time slots, and focusing on effort and activity around major releases. Such analyses have the objective of evaluating effort, productivity and types of activity globally and around major releases. They enable a comparison of these releases and patterns of effort and activities with traditional software products and processes, and in turn, the identification of company-driven projects (i.e., working mainly during office hours) among FLOSS endeavors. The results of this research show that, overall, the effort within the Linux kernel community is constant (albeit at different levels) throughout the week, signalling the need of updated estimation models, different from those used in traditional 9am–5pm, Monday to Friday commercial companies. It also becomes evident that the activity before a release is vastly different from after a release, and that the changes show an increase in code complexity in specific time slots (notably in the late night hours), which will later require additional maintenance efforts.

Measuring Open Source Quality

There is an ample debate over the quality of Free/Libre Open Source Software (FLOSS) with mixed research results. The authors show that a reason for these mixed results is that quality is being defined, measured, and evaluated differently. They report the most popular approaches including software structure measures, process measures, and maturity assessment models. The way researchers have built their samples has also contributed to the mixed results with different project properties being considered and ignored. Because FLOSS projects evolve with each release, their quality does too, and it must be measured using metrics that take into account their communities’ commitment to quality rather than just the structure of the resulting code. Challenges exist in defining what constitutes a defect or bug, and the role of modularity in affecting FLOSS quality. The authors suggest three considerations for future research on FLOSS quality models: (1) defect resolution rate, (2) kind of software product, and (3) modularity—both technical and organizational.

Adopting Free/Libre/Open Source Software Practices, Techniques and Methods for Industrial Use

Today’s software companies face the challenges of highly distributed development projects and constantly changing requirements. This paper proposes the adoption of relevant Free/Libre/Open Source Software (FLOSS) practices in order to improve software development projects in industry. Many FLOSS projects have proven to be very successful, producing high quality products with steady and frequent releases. This study aims to identify FLOSS practices that can be adapted for the corporate environment. To achieve this goal, a framework to compare FLOSS and industrial development methodologies was created. Three successful FLOSS projects were selected as study targets (the Linux Kernel, the FreeBSD operating system, and the JBoss application server), as well as two projects from Ericsson, a large telecommunications company. Based on an analysis of these projects, FLOSS best practices were tailored to fit industrial development environments. The final results consisted of a set of key adoption opportunities that aimed to improve software quality and overall development productivity by importing best practices from the FLOSS environment. The adoption opportunities were then validated at three large corporations.

Can Open Source Projects Succeed When the Producers are Not Users? Lessons from the Data Processing Field.

Free/Libre Open Source Software (FLOSS) proposes an original way to solve the incentive dilemma for the production of information goods, based on von~Hippel (1988)'s user-as-innovator principle: as users benefit from innovation, they have incentive to produce it, and as they can expect cumulative innovation on their own proposition, they have incentive to share it. But what is the incentive for producers when they are not users? We discuss this question via a quantitative study of FLOSS projects in “algorithm-based industries”. We find that in that case producers hardly participate in such projects.

What Makes Free/Libre Open Source Software (FLOSS) Projects Successful? An Agent-Based Model of FLOSS Projects

The last few years have seen a rapid increase in the number of Free/Libre Open Source Software (FLOSS) projects. Some of these projects, such as Linux and the Apache web server, have become phenomenally successful. However, for every successful FLOSS project there are dozens of FLOSS projects which never succeed. These projects fail to attract developers and/or consumers and, as a result, never get off the ground. The aim of this research is to better understand why some FLOSS projects flourish while others wither and die. This article presents a simple agent-based model that is calibrated on key patterns of data from SourceForge, the largest online site hosting open source projects. The calibrated model provides insight into the conditions necessary for FLOSS success and might be used for scenario analysis of future developments of FLOSS.

Teaching Software Engineering with Free/Libre Open Source Projects

One of the major problems in software engineering education is the involvement of students in real world software projects. Industry projects are a solution, but in many cases they are hard to find and student participation can be problematic due to cultural, familiarization and other practical reasons. The abundance of Free / Libre Open Source Software (FLOSS) projects is a neat solution, offering multi-lingual, multicultural environments in virtually every application domain, at different levels of project size, maturity, organization etc. The paper analyzes how acquisition of practical experience on several basic and advanced software engineering topics can be achieved by working in a FLOSS project. The kind of skills that can be acquired are those requested by the Overview Report for Computing Curricula by ACM and topics examined are those of the Software Engineering Body of Knowledge, by IEEE. Also software engineering areas that require special care or that may not prove suitable for such treatment are identified. Various isolated teaching cases pertaining to this approach are presented and discussed.

Identifying exogenous drivers and evolutionary stages in FLOSS projects

The success of a Free/Libre/Open Source Software (FLOSS) project has been evaluated in the past through the number of commits made to its configuration management system, number of developers and number of users. Most studies, based on a popular FLOSS repository (SourceForge), have concluded that the vast majority of projects are failures. This study’s empirical results confirm and expand conclusions from an earlier and more limited work. Not only do projects from different repositories display different process and product characteristics, but a more general pattern can be observed. Projects may be considered as early inceptors in highly visible repositories, or as established projects within desktop-wide projects, or finally as structured parts of FLOSS distributions. These three possibilities are formalized into a framework of transitions between repositories. The framework developed here provides a wider context in which results from FLOSS repository mining can be more effectively presented. Researchers can draw different conclusions based on the overall characteristics studied about an Open Source software project’s potential for success, depending on the repository that they mine. These results also provide guidance to OSS developers when choosing where to host their project and how to distribute it to maximize its evolutionary success.

Dynamics of innovation in an "open source" collaboration environment: lurking, laboring, and launching FLOSS projects on SourceForge

A systems analysis perspective is adopted to examine the critical properties of the Free/Libre/Open Source Software (FLOSS) mode of innovation, as reflected on the SourceForge platform (SF.net). This approach re-scales March's (1991) framework and applies it to characterize the “innovation system” of a “distributed organization” of interacting agents in a virtual collaboration environment, rather than to innovation within a firm. March (1991) views the process of innovation at the organizational level as the coupling of sub-processes of exploration and exploitation. Correspondingly, the innovation system of the virtual collaboration environment represented by SF.net is an emergent property of two “coupled” processes: one involves the interactions among agents searching the locale for information and knowledge resources to use in designing novel software products (i.e., exploration), and the other involves the mobilization of individuals’ capabilities for application in the software development projects that become established on the platform (i.e., exploitation). The micro-dynamics of this system are studied empirically by constructing transition probability matrices representing the movements of 222,835 SF.net users among seven different activity states, which range from “lurking” (not contributing or contributing to projects without becoming a member) to “laboring” (joining one or more projects as members), and to “launching” (founding one or more projects) within each successive 6-month interval. The estimated probabilities are found to form first-order Markov chains describing ergodic processes. This makes it possible the computation of the equilibrium distribution of agents among the states, thereby suppressing transient effects and revealing persisting patterns of project joining and project launching. The latter show the FLOSS innovation process on SF.net to be highly dissipative: a very large proportion of the registered “developers” fail to become even minimally active on the platform. There is nevertheless an active core of mobile project joiners, and a (still smaller) core of project founders who persist in creating new projects. The structure of these groups’ interactions (as displayed within the 3-year period examined) is investigated in detail, and it is shown that it would be sufficient to sustain both the exploration and exploitation phases of the platform's global dynamics.

Evolutionary Success of Open Source Software: an Investigation into Exogenous Drivers

The “success” of a Free/Libre/Open Source Software (FLOSS) project has often been evaluated through the number of commits made to its configuration management system, number of developers and number of users. Based on Source- Forge, most studies have concluded that the vast majority of projects are failures. This paper argues that the relative success of a FLOSS project can depend also on the chosen forge and distribution. Given a random sample of 50 projects contained within a popular FLOSS forge (Debian, which is the basis of the successful Debian distribution), we compare these with a similar sample from SourceForge, using product and process metrics, such as size achieved and number of developers involved. The results show firstly that, depending on the forge of FLOSS projects, researchers can draw different conclusions regarding what constitutes a successful FLOSS project. Secondly, the projects included in the Debian distribution benefit, on average, from more evolutionary activity and more developers than the comparable projects on SourceForge. Finally, the Debian projects start to benefit from more activity and more developers from the point at which they join this distribution.

Editorial

**Editorial** Science Studies 1/2007 is the first issue by its new chief editors Dr. Tarja Knuuttila and Docent Sampsa Hyysalo. The decision to appoint two editors-in-chief was motivated by the steadily increasing amount of submissions, as well as by the need to retain a good grasp of the range of focal areas that comprise science and technology studies. Tarja Knuuttila is a philosopher of science currently studying scientific modelling and representation especially in the context of computational science. Sampsa Hyysalo’s primary field is science and technology studies. He has studied change in professional and everyday practices by focussing on the development and appropriation of health ICTs. The change in its editors does not mark a great transition in the focus of the journal. Science Studies continues to be both an international and interdisciplinary journal welcoming contributions to the study of science and technology from different points of view and different disciplinary backgrounds whether philosophical, historical, sociological, psychological, educational or politicoeconomic. At the moment the journal receives contributions from all over the world, the most contributions coming from the US and from Northern European countries. The acceptance rate is 20,5 for the moment, but it will fall, since we are receiving an increasing amount of contributions. This shows that the interest towards Science Studies is steadily growing. As to our website, Science Studies is also happy to announce that it has digitized and published all of its articles from 1988 to 1997. The ten volumes which have been published comprise over 100 articles on Science and Technology Studies and represent one of the largest fully accessible online collections available today. We are committed to distributing the content of Science Studies to as broad an audience as possible at no cost. Moreover, we have decreased our moving wall from one year to six months, allowing for increased visibility and access to our most recent content. The present volume contains four full articles concentrating mainly on science and science policy. In “From Core Set to Assemblage: On the Dynamics of Exclusion and Inclusion in the Failure to Derive Beta Cells from Embryonic Stem Cells” Mike Michael et al. concentrate on a traditional STS-theme, that of experimenter’s regress. They contrast Collins’s core set model to an analysis in terms of assemblages in an attempt to show that scientific controversies need not end in the exclusion of the discredited faction of scientists from the core set. Rather, due to several reasons such as the ‘chronic uncertainty’ of stem cell research, the epistemically defeated faction can be rehabilitated because of the ‘social understandability’ of their strategies. ”Effects of ‘Mode 2’-Related Policy on the Research Process: The Case of Publicly Funded German Nanotechnology” by Andreas Wald and “Disentangling Transdisciplinarity: An Analysis of Knowledge Integration in Problem-Oriented Research” by Wolfgang Zierhofer and Paul Burger provide somewhat critical perspectives on the supposed advantages of Mode 2 policies and the very idea that transdisciplinary research, which is also referred to as Mode 2 science, represents a genuinely new model of knowledge production. Wald argues that nanotechnology research does not fit into the picture portrayed by Mode 2 literature, yet Mode 2-related policies are applied to it in the German context. As a result of this, policies are often considered harmful by the scientists. Zierhofer and Burger in turn seek to analyze the diversity of the supposed transdisciplinary mode of knowledge production in terms of various types of research objectives and related research instruments. Finally, Matt Ratto’s paper “A Practice-Based Model of Access for Science: Linux Kernel Development and Shared Digital Resources” presents a close-quarter analysis of Linux kernel development in order to build a model of access that would be apt for examining the increasingly distributed and digitally-mediated scientific work. This last paper is also a teaser for the next issue of Science Studies, which is a special issue on Free/Libre Open source software (FLOSS). Guest edited by Dr. Yuwei Lin and Prof. Lars Risan, Science Studies 2/2007 provides a set of highly interesting and in-depth studies on organization, work and development in FLOSS projects.

The Material and Social Dynamics of Motivation

Volunteer motivation has been a central theme in Free/Libre/Open Source Software (FLOSS) literature. This research has been largely dominated by economists who rely in their surveys on the distinction between intrinsic and extrinsic motivations and the ‘hacker ethic’ – for profi t juxtaposition. The paper argues that survey-based analytical frameworks and research designs have led to a focus on some motivational attributions at the expense of others. It then presents a case study that explores dynamic, non-individualistic and content-sensitive aspects of motivations. The approach is based on socio-cultural psychology and the author’s observations of a hybrid fi rm-community FLOSS project, OpenOffi ce.org. Instead of separating intrinsic motivations from extrinsic ones, it is argued that complex and changing patterns of motivations are tied to changing objects and personal histories prior to and during participation. The boundary between work and hobby in an individual’s participation path is blurred and shifting.