EDBT 2026 Demo / reviewers in the wild / expert
Klaas-Jan Stol
dblp:08/7091
· DBLP profile ↗
43ranked-venue papers
14as first author
22since 2021 · last 2026
0000-0002-1038-5050ORCID · verified
Domains — the database's venue-derived domains; a paper can count in several
Software engineering, systems software and programming languages · 39 · 13 first-author · 19 since 2021Databases, data management, data science and information retrieval · 2 · 1 first-author · 2 since 2021Security and privacy · 1 · 1 since 2021Applied, interdisciplinary, general and emerging computing · 1
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2026 | Maintaining shared understanding of non-functional requirements in small companies using continuous software engineering
Colin M. Werner, Laura Okpara, Klaas-Jan Stol, Daniela E. Damian |
Empir. Softw. Eng. | 3 |
| 2026 | User stories as boundary objects in agile requirements engineering: A theoretical literature reviewabstractUser stories have become the predominant method for managing requirements in software development, used by approximately half of all software developers. Despite this widespread adoption, there is limited theoretical understanding of how user stories are used in practice. Through a theoretical literature review of 14 industry studies, we develop five theoretical propositions: 1) user stories facilitate shared understanding between developers and users; 2) small user stories help developers cope with change; 3) clarifying the ‘why’ in user stories reinforces focus on user needs but adds complexity to the development process; 4) conversations triggered by user stories can hamper the sense of productivity; and 5) user stories as recorded in writing degrade over time. Using boundary object theory as an analytical lens, we explain how user stories facilitate knowledge transfer across syntactic, semantic, and pragmatic boundaries between developers and users. This theoretical lens offers new insights into why some user stories succeed while others fail to bridge boundaries between users and developers. The review highlights the sharp contrast between the widespread use of user stories among practitioners and the limited academic research on their practical application. We end with identifying opportunities for future research, particularly on how user stories can be used in the era of generative AI. Tor Sporsem, Torgeir Dingsøyr, Klaas-Jan Stol |
J. Syst. Softw. | 3 |
| 2026 | Onboarding Software Professionals in a Hybrid WorldabstractOnboarding is an important activity to integrate new employees into an organization as soon as possible, in order to support them in becoming productive. Whereas onboarding has traditionally been done primarily onsite, it is now increasingly common for new software professionals to be onboarded either fully remotely or partially remotely in hybrid settings. We ask how software professionals develop a sense of belonging through the onboarding process. Using a conceptual framework from the general onboarding literature, we report on case studies of onboarding of software professionals in three different settings on the hybrid continuum, drawing on a dataset comprising interviews with 46 informants, Slack logs, observations, and company documents. In Case 1, we focus on the onboarding of consultant developers in two divisions: in one division, the consultants work internally with the consulting organization. In the other division, the consultants are placed with clients. In Case 2, we study the onboarding of software professionals in a hybrid setting, and in Case 3, we study the onboarding of a new team of remote developers based in Portugal, who joined a company in Norway. We extend the literature on onboarding of software professionals by shedding light on how software organizations conduct onboarding in different types of hybrid settings. We extend and refine the initial conceptual model, and formalize it through the development of a series of propositions. We then discuss a number of recommendations for software organizations who wish to onboard new software professionals in different settings on the hybrid continuum. Klaas-Jan Stol, Viktoria Stray, Nils Brede Moe, Tor Sporsem |
IEEE Trans. Software Eng. | 1 |
| 2025 | The Insider's Dilemma: Employed Open Source Developers' Identification Imbalance and Intentions to LeaveabstractIn corporate-sponsored open source software development, company-employed developers become “insiders” to the OSS community, and therefore have two roles: they serve as a representative of their employing company, but may also identify as a member of the open source community. This study investigates what happens when identification with the company exceeds identification with the community (and vice versa), and also focuses on consequences when these insider roles come in conflict. Informed by social identity theory and organization-profession conflict theory, we report on two studies that predict identification imbalance to affect company turnover intention. Our first study is based on a survey of employed Linux kernel developers and uses polynomial regression to assess the effect of identification imbalance (and congruence) on company turnover intention. The second study extends our investigation beyond Linux and demonstrates that the effect of identification imbalance on turnover intention is mediated by role conflict. The findings suggest that turnover intention is lowest, when company and community identification match at high rather than low levels. We also find developers’ company career ambition influences how role conflict relates to company turnover intention. This study holds implications for theory and for managers in companies who engage with OSS communities. Mario Schaarschmidt, Klaas-Jan Stol, Brian Fitzgerald 0001 |
Eur. J. Inf. Syst. | 2 |
| 2025 | What is Generative AI good for? Introduction to the special issue on Generative AI in software engineering
Viktoria Stray, Geir Kjetil Hanssen, Astri Barbala, Darja Smite, Klaas-Jan Stol |
Inf. Softw. Technol. | 5 |
| 2024 | How Are Paid and Volunteer Open Source Developers Different? A Study of the Rust ProjectabstractIt is now commonplace for organizations to pay developers to work on specific open source software (OSS) projects to pursue their business goals. Such paid developers work alongside voluntary contributors, but given the different motivations of these two groups of developers, conflict may arise, which may pose a threat to a project's sustainability. This paper presents an empirical study of paid developers and volunteers in Rust, a popular open source programming language project. Rust is a particularly interesting case given considerable concerns about corporate participation. We compare volunteers and paid developers through contribution characteristics and long-term participation, and solicit volunteers' perceptions on paid developers. We find that core paid developers tend to contribute more frequently; commits contributed by onetime paid developers have bigger sizes; peripheral paid developers implement more features; and being paid plays a positive role in becoming a long-term contributor. We also find that volunteers do have some prejudices against paid developers. This study suggests that the dichotomous view of paid vs. volunteer developers is too simplistic and that further subgroups can be identified. Companies should become more sensitive to how they engage with OSS communities, in certain ways as suggested by this study. Yuxia Zhang, Klaas-Jan Stol, Minghui Zhou 0001, Hui Liu 0003 |
ICSE | 3 |
| 2024 | Does adopting inner source increase job satisfaction? A social capital perspective using a mixed-methods approachabstractInternal boundaries between information systems divisions have traditionally caused friction and frustration, and negatively affected IT staff job satisfaction. Adopting open source development principles and processes within a corporate environment, what has been labeled ‘inner source,’ is now part of a larger management strategy to break down silos and promote innovation, collaboration, cooperation and communication across divisions of an organization. In this article we argue that inner source emphasizes the importance of relationships between developers and teams interacting across intra-organizational boundaries. We posit that inner source helps to create social capital, which in turn links to higher levels of job satisfaction. We use a sequential mixed-methods approach to test a theoretical model by combining quantitative survey data collected at one IT organization with qualitative data based on interviews with professionals from six organizations that adopted inner source. The results suggest that employees who participate in inner source projects develop more social interaction ties with others and have higher levels of shared understanding of software projects. Furthermore, we confirm that social interaction ties and a shared understanding link to a higher degree of trust. Finally, this study provides evidence that social capital mediates the link between participation in inner source and job satisfaction, implying that an inner source strategy can offer benefits to organizations. Enriched with the findings from the qualitative interviews, we then identify a number of implications for managers. Klaas-Jan Stol, Mario Schaarschmidt, Lorraine Morgan |
J. Strateg. Inf. Syst. | 1 |
| 2024 | Generative AI in Software Engineering Must Be Human-Centered: The Copenhagen Manifesto
Daniel Russo 0002, Sebastian Baltes, Niels van Berkel, Paris Avgeriou, Fabio Calefato, Beatriz Cabrero-Daniel, Gemma Catolino, Jürgen Cito, Neil A. Ernst, Thomas Fritz 0001, Hideaki Hata, Reid Holmes, Maliheh Izadi, Foutse Khomh, Mikkel Baun Kjærgaard, Grischa Liebel, Alberto Lluch-Lafuente, Stefano Lambiase, Walid Maalej, Gail C. Murphy, Nils Brede Moe, Gabrielle O'Brien, Elda Paja, Mauro Pezzè, John Stouby Persson, Rafael Prikladnicki, Paul Ralph, Martin P. Robillard, Thiago Rocha Silva, Klaas-Jan Stol, Margaret-Anne D. Storey, Viktoria Stray, Paolo Tell, Christoph Treude, Bogdan Vasilescu |
J. Syst. Softw. | 30 |
| 2024 | Communicating Study Design Trade-offs in Software EngineeringabstractReflecting on the limitations of a study is a crucial part of the research process. In software engineering studies, this reflection is typically conveyed through discussions of study limitations or threats to validity. In current practice, such discussions seldom provide sufficient insight to understand the rationale for decisions taken before and during the study, and their implications. We revisit the practice of discussing study limitations and threats to validity and identify its weaknesses. We propose to refocus this practice of self-reflection to a discussion centered on the notion of trade-offs . We argue that documenting trade-offs allows researchers to clarify how the benefits of their study design decisions outweigh the costs of possible alternatives. We present guidelines for reporting trade-offs in a way that promotes a fair and dispassionate assessment of researchers’ work. Martin P. Robillard, Deeksha M. Arya, Neil A. Ernst, Jin L. C. Guo, Maxime Lamothe, Mathieu Nassif, Nicole Novielli, Alexander Serebrenik, Igor Steinmacher, Klaas-Jan Stol |
ACM Trans. Softw. Eng. Methodol. | 10 |
| 2024 | Acrobats and Safety Nets: Problematizing Large-Scale Agile Software DevelopmentabstractAgile development methods have become a standard in the software industry, including in large-scale projects. These methods share a set of underlying assumptions that distinguish them from more traditional plan-driven approaches. In this article, we adopt Alvesson and Sandberg's problematization approach to challenge three key assumptions that are prevalent in the large-scale agile literature: (1) agile and plan-driven methods are mutually exclusive; (2) self-managing and hierarchically organized teams are mutually exclusive; and (3) agile methods can scale through simple linear composition. Using a longitudinal case study of large-scale agile development, we describe a series of trigger events and episodes whereby the agile approach was tailored to address the needs of the large-scale development context, which was very much at odds with these fundamental assumptions. We develop a set of new underlying assumptions which suggest that agile and plan-driven practices are mutually enabling and necessary for coordination and scaling in large-scale agile projects. We develop nine propositions for large-scale agile projects based on these new alternative underlying assumptions. Finally, we summarize our theoretical contribution in a generic process model of continuously adjusting agile and plan-driven practices in order to accommodate process challenges in large-scale agile projects. Knut H. Rolland, Brian Fitzgerald 0001, Torgeir Dingsøyr, Klaas-Jan Stol |
ACM Trans. Softw. Eng. Methodol. | 4 |
| 2024 | Predicting Attrition among Software Professionals: Antecedents and Consequences of Burnout and EngagementabstractIn this study of burnout and engagement, we address three major themes. First, we offer a review of prior studies of burnout among IT professionals and link these studies to the Job Demands-Resources (JD-R) model. Informed by the JD-R model, we identify three factors that are organizational job resources and posit that these (a) increase engagement and (b) decrease burnout. Second, we extend the JD-R by considering software professionals’ intention to stay as a consequence of these two affective states, burnout and engagement. Third, we focus on the importance of factors for intention to stay, and actual retention behavior. We use a unique dataset of over 13,000 respondents at one global IT organization, enriched with employment status 90 days after the initial survey. Leveraging partial-least squares structural quation modeling and machine learning, we find that the data mostly support our theoretical model, with some variation across different subgroups of respondents. An importance-performance map analysis suggests that managers may wish to focus on interventions regarding burnout as a predictor of intention to leave. The Machine Learning model suggests that engagement and opportunities to learn are the top two most important factors that explain whether software professionals leave an organization. Bianca Trinkenreich, Fabio Santos, Klaas-Jan Stol |
ACM Trans. Softw. Eng. Methodol. | 3 |
| 2024 | Automatic Commit Message Generation: A Critical Review and Directions for Future WorkabstractCommit messages are critical for code comprehension and software maintenance. Writing a high-quality message requires skill and effort. To support developers and reduce their effort on this task, several approaches have been proposed to automatically generate commit messages. Despite the promising performance reported, we have identified three significant and prevalent threats in these automated approaches: 1) the datasets used to train and evaluate these approaches contain a considerable amount of ‘noise’; 2) current approaches only consider commits of a limited diff size; and 3) current approaches can only generate the subject of a commit message, not the message body. The first limitation may let the models ‘learn’ inappropriate messages in the training stage, and also lead to inflated performance results in their evaluation. The other two threats can considerably weaken the practical usability of these approaches. Further, with the rapid emergence of large language models (LLMs) that show superior performance in many software engineering tasks, it is worth asking: can LLMs address the challenge of long diffs and whole message generation? This article first reports the results of an empirical study to assess the impact of these three threats on the performance of the state-of-the-art auto generators of commit messages. We collected commit data of the Top 1,000 most-starred Java projects in GitHub and systematically removed noisy commits with bot-submitted and meaningless messages. We then compared the performance of four approaches representative of the state-of-the-art before and after the removal of noisy messages, or with different lengths of commit diffs. We also conducted a qualitative survey with developers to investigate their perspectives on simply generating message subjects. Finally, we evaluate the performance of two representative LLMs, namely UniXcoder and ChatGPT, in generating more practical commit messages. The results demonstrate that generating commit messages is of great practical value, considerable work is needed to mature the current state-of-the-art, and LLMs can be an avenue worth trying to address the current limitations. Our analyses provide insights for future work to achieve better performance in practice. Yuxia Zhang, Zhiqing Qiu, Klaas-Jan Stol, Yingchen Tian, Hui Liu 0003 |
IEEE Trans. Software Eng. | 3 |
| 2023 | Unhelpful Assumptions in Software Security ResearchabstractIn the study of software security many factors must be considered. Once venturing beyond the simplest of laboratory experiments, the researcher is obliged to contend with exponentially complex conditions. Software security has been shown to be affected by priming, tool usability, library documentation, organisational security culture, the content and format of internet resources, IT team and developer interaction, Internet search engine ordering, developer personality, security warning placement, mentoring, developer experience and more. In a systematic review of software security papers published since 2016, we have identified a number of unhelpful assumptions that are commonly made by software security researchers. In this paper we list these assumptions, describe why they sometimes do not reflect reality, and suggest implications for researchers. Ita Ryan, Utz Roedig, Klaas-Jan Stol |
CCS | 3 |
| 2023 | Measuring Secure Coding Practice and Culture: A Finger Pointing at the Moon is not the MoonabstractSoftware security research has a core problem: it is impossible to prove the security of complex software. A low number of known defects may simply indicate that the software has not been attacked yet, or that successful attacks have not been detected. A high defect count may be the result of white-hat hacker targeting, or of a successful bug bounty program which prevented insecurities from persisting in the wild. This makes it difficult to measure the security of non-trivial software. Researchers instead usually measure effort directed towards ensuring software security. However, different researchers use their own tailored measures, usually devised from industry secure coding guidelines. Not only is there no agreed way to measure effort, there is also no agreement on what effort entails. Qualitative studies emphasise the importance of security culture in an organisation. Where software security practices are introduced solely to ensure compliance with legislative or industry standards, a box-ticking attitude to security may result. The security culture may be weak or non-existent, making it likely that precautions not explicitly mentioned in the standards will be missed. Thus, researchers need both a way to assess software security practice and a way to measure software security culture. To assess security practice, we converted the empirically-established 12 most common software security activities into questions. To assess security culture, we devised a number of questions grounded in prior literature. We ran a secure development survey with both sets of questions, obtaining organic responses from 1,100 software coders in 59 countries. We used proven common activities to assess security practice, and made a first attempt to quantitatively assess aspects of security culture in the broad developer population. Our results show that some coders still work in environments where there is little to no attempt to ensure code security. Security practice and culture do not always correlate, and some organisations with strong secure coding practice have weak secure coding culture. This may lead to problems in defect prevention and sustained software security effort. Ita Ryan, Utz Roedig, Klaas-Jan Stol |
ICSE | 3 |
| 2023 | Do I Belong? Modeling Sense of Virtual Community Among Linux Kernel ContributorsabstractThe sense of belonging to a community is a basic human need that impacts an individual's behavior, long-term engagement, and job satisfaction, as revealed by research in disciplines such as psychology, healthcare, and education. Despite much research on how to retain developers in Open Source Software (OSS) projects and other virtual, peer-production communities, there is a paucity of research investigating what might contribute to a sense of belonging in these communities. To that end, we develop a theoretical model that seeks to understand the link between OSS developer motives and a Sense of Virtual Community (SVC). We test the model with a dataset collected in the Linux Kernel developer community (N=225), using structural equation modeling techniques. Our results for this case study show that intrinsic motivations (social or hedonic motives) are positively associated with a sense of virtual community, but living in an authoritative country and being paid to contribute can reduce the sense of virtual community. Based on these results, we offer suggestions for open source projects to foster a sense of virtual community, with a view to retaining contributors and Improving projects' sustainability. Bianca Trinkenreich, Klaas-Jan Stol, Anita Sarma, Daniel M. Germán, Marco Aurélio Gerosa, Igor Steinmacher |
ICSE | 2 |
| 2023 | Knowns and Unknowns: An Experience Report on Discovering Tacit Knowledge of Maritime Surveyorsabstract[Context] Requirements elicitation is an essential activity to ensure that systems provide the necessary functionality to users, and that they are fit for purpose. In addition to traditional ‘reductionist’ techniques, the use of observations and ethnography-style techniques have been proposed to identify requirements. [Research Problem] One frequently heard issue with observational techniques is that they are costly to use, as developers who would partake, would lose considerable development time. Observation also does not guarantee that all essential requirements are identified, and so luck plays a role. Very few experience reports exist to evaluate observational techniques in practice, and for organizations it is difficult to assess whether observation is a worthwhile activity, given its associated cost. [Results] This report presents experiences from DNV, a global leader providing maritime services who are renewing an information system to support its expert users. We draw on several data sources, covering insights from both developers and users. The data were collected through 9 interviews with users and developers, and over 80 h of observation of prospective users in the maritime domain. We capture ‘knowns’ and ‘unknowns’ from both developers and users, and highlight the importance of observational studies. [Contribution] While observational techniques are costly to use, we conclude that essential information is uncovered, which is key for developers to understand system users and their concerns. Tor Sporsem, Morten Hatling, Anastasiia Tkalich, Klaas-Jan Stol |
REFSQ | 4 |
| 2022 | What Makes a Good Commit Message?abstractA key issue in collaborative software development is communication among developers. One modality of communication is a commit message, in which developers describe the changes they make in a repository. As such, commit messages serve as an "audit trail" by which developers can understand how the source code of a project has changed---and why. Hence, the quality of commit messages affects the effectiveness of communication among developers. Commit messages are often of poor quality as developers lack time and motivation to craft a good message. Several automatic approaches have been proposed to generate commit messages. However, these are based on uncurated datasets including considerable proportions of poorly phrased commit messages. In this multi-method study, we first define what constitutes a "good" commit message, and then establish what proportion of commit messages lack information using a sample of almost 1,600 messages from five highly active open source projects. We find that an average of circa 44% of messages could be improved, suggesting the use of uncurated datasets may be a major threat when commit message generators are trained with such data. We also observe that prior work has not considered semantics of commit messages, and there is surprisingly little guidance available for writing good commit messages. To that end, we develop a taxonomy based on recurring patterns in commit messages' expressions. Finally, we investigate whether "good" commit messages can be automatically identified; such automation could prompt developers to write better commit messages. Yingchen Tian, Yuxia Zhang, Klaas-Jan Stol, Hui Liu 0003 |
ICSE | 3 |
| 2022 | Corporate dominance in open source ecosystems: a case study of OpenStackabstractCorporate participation plays an increasing role in Open Source Software (OSS) development. Unlike volunteers in OSS projects, companies are driven by business objectives. To pursue corporate interests, companies may try to dominate the development direction of OSS projects. One company's domination in OSS may 'crowd out' other contributors, changing the nature of the project, and jeopardizing the sustainability of the OSS ecosystem. Prior studies of corporate involvement in OSS have primarily focused on predominately positive aspects such as business strategies, contribution models, and collaboration patterns. However, there is a scarcity of research on the potential drawbacks of corporate engagement. In this paper, we investigate corporate dominance in OSS ecosystems. We draw on the field of Economics and quantify company domination using a dominance measure; we investigate the prevalence, patterns, and impact of domination in the evolution of the OpenStack ecosystem. We find evidence of company domination in over 73% of the repositories in OpenStack, and approximately 25% of companies dominate one or more repositories per version. We identify five patterns of corporate dominance: Early incubation, Full-time hosting, Growing domination, Occasional domination, and Last remaining. We find that domination has a significantly negative relationship with the survival probability of OSS projects. This study provides insights for building sustainable relationships between companies and the OSS ecosystems in which they seek to get involved. Yuxia Zhang, Klaas-Jan Stol, Hui Liu 0003, Minghui Zhou 0001 |
ESEC/SIGSOFT FSE | 2 |
| 2022 | From anecdote to evidence: the relationship between personality and need for cognition of developersabstractThere is considerable anecdotal evidence suggesting that software engineers enjoy engaging in solving puzzles and other cognitive efforts. A tendency to engage in and enjoy effortful thinking is referred to as a person's 'need for cognition.' In this article we study the relationship between software engineers' personality traits and their need for cognition. Through a large-scale sample study of 483 respondents we collected data to capture the six 'bright' personality traits of the HEXACO model of personality, and three 'dark' personality traits. Data were analyzed using several methods including a multiple Bayesian linear regression analysis. The results indicate that ca. 33% of variation in developers' need for cognition can be explained by personality traits. The Bayesian analysis suggests four traits to be of particular interest in predicting need for cognition: openness to experience, conscientiousness, honesty-humility, and emotionality. Further, we also find that need for cognition of software engineers is, on average, higher than in the general population, based on a comparison with prior studies. Given the importance of human factors for software engineers' performance in general, and problem solving skills in particular, our findings suggest several implications for recruitment, working behavior, and teaming. Daniel Russo 0002, Andrés R. Masegosa, Klaas-Jan Stol |
Empir. Softw. Eng. | 3 |
| 2022 | Gamification in software engineering: the mediating role of developer engagement and job satisfaction
Klaas-Jan Stol, Mario Schaarschmidt, Shelly Goldblit |
Empir. Softw. Eng. | 1 |
| 2022 | Managing Episodic Volunteers in Free/Libre/Open Source Software CommunitiesabstractWe draw on the concept of episodic volunteering (EV) from the general volunteering literature to identify practices for managing EV in free/libre/open source software (FLOSS) communities. Infrequent but ongoing participation is widespread, but the practices that community managers are using to manage EV, and their concerns about EV, have not been previously documented. We conducted a policy Delphi study involving 24 FLOSS community managers from 22 different communities. Our panel identified 16 concerns related to managing EV in FLOSS, which we ranked by prevalence. We also describe 65 practices for managing EV in FLOSS. Almost three-quarters of these practices are used by at least three community managers. We report these practices using a systematic presentation that includes context, relationships between practices, and concerns that they address. These findings provide a coherent framework that can help FLOSS community managers to better manage episodic contributors. Ann Barcomb, Klaas-Jan Stol, Brian Fitzgerald 0001, Dirk Riehle |
IEEE Trans. Software Eng. | 2 |
| 2022 | Gender Differences in Personality Traits of Software EngineersabstractThere is a growing body of gender studies in software engineering to understand diversity and inclusion issues, as diversity is recognized to be a key issue to healthy teams and communities. A second factor often linked to team performance is personality, which has received far more attention. Very few studies, however, have focused on the intersection of these two fields. Hence, we set out to study gender differences in personality traits of software engineers. Through a survey study we collected personality data, using the HEXACO model, of 483 software engineers. The data were analyzed using a Bayesian independent sample t-test and network analysis. The results suggest that women score significantly higher in Openness to Experience, Honesty-Humility, and Emotionality than men. Further, men show higher psychopathic traits than women. Based on these findings, we develop a number of propositions that can guide future research. Daniel Russo 0002, Klaas-Jan Stol |
IEEE Trans. Software Eng. | 2 |
| 2020 | How do companies collaborate in open source ecosystems?: an empirical study of OpenStackabstractOpen Source Software (OSS) has come to play a critical role in the software industry. Some large ecosystems enjoy the participation of large numbers of companies, each of which has its own focus and goals. Indeed, companies that otherwise compete, may become collaborators within the OSS ecosystem they participate in. Prior research has largely focused on commercial involvement in OSS projects, but there is a scarcity of research focusing on company collaborations within OSS ecosystems. Some of these ecosystems have become critical building blocks for organizations worldwide; hence, a clear understanding of how companies collaborate within large ecosystems is essential. This paper presents the results of an empirical study of the OpenStack ecosystem, in which hundreds of companies collaborate on thousands of project repositories to deliver cloud distributions. Based on a detailed analysis, we identify clusters of collaborations, and identify four strategies that companies adopt to engage with the OpenStack ecosystem. We alsofind that companies may engage in intentional or passive collaborations, or may work in an isolated fashion. Further, wefi nd that a company's position in the collaboration network is positively associated with its productivity in OpenStack. Our study sheds light on how large OSS ecosystems work, and in particular on the patterns of collaboration within one such large ecosystem. Yuxia Zhang, Minghui Zhou 0001, Klaas-Jan Stol, Zhi Jin 0001 |
ICSE | 3 |
| 2020 | Exploring onboarding success, organizational fit, and turnover intention of software professionals
Gaurav G. Sharma, Klaas-Jan Stol |
J. Syst. Softw. | 2 |
| 2020 | Uncovering the Periphery: A Qualitative Survey of Episodic Volunteering in Free/Libre and Open Source Software CommunitiesabstractFree/Libre and Open Source Software (FLOSS) communities are composed, in part, of volunteers, many of whom contribute infrequently. However, these infrequent volunteers contribute to the sustainability of FLOSS projects, and should ideally be encouraged to continue participating, even if they cannot be persuaded to contribute regularly. Infrequent contributions are part of a trend which has been widely observed in other sectors of volunteering, where it has been termed “episodic volunteering” (EV). Previous FLOSS research has focused on the Onion model, differentiating core and peripheral developers, with the latter considered as a homogeneous group. We argue this is too simplistic, given the size of the periphery group and the myriad of valuable activities they perform beyond coding. Our exploratory qualitative survey of 13 FLOSS communities investigated what episodic volunteering looks like in a FLOSS context. EV is widespread in FLOSS communities, although not specifically managed. We suggest several recommendations for managing EV based on a framework drawn from the volunteering literature. Also, episodic volunteers make a wide range of value-added contributions other than code, and they should neither be expected nor coerced into becoming habitual volunteers. Ann Barcomb, Andreas Kaufmann, Dirk Riehle, Klaas-Jan Stol, Brian Fitzgerald 0001 |
IEEE Trans. Software Eng. | 4 |
| 2019 | Why do episodic volunteers stay in FLOSS communities?abstractSuccessful Free/Libre and Open Source Software (FLOSS) projects incorporate both habitual and infrequent, or episodic, contributors. Using the concept of episodic volunteering (EV) from the general volunteering literature, we derive a model consisting of five key constructs that we hypothesize affect episodic volunteers' retention in FLOSS communities. To evaluate the model we conducted a survey with over 100 FLOSS episodic volunteers. We observe that three of our model constructs (social norms, satisfaction and community commitment) are all positively associated with volunteers' intention to remain, while the two other constructs (psychological sense of community and contributor benefit motivations) are not. Furthermore, exploratory clustering on unobserved heterogeneity suggests that there are four distinct categories of volunteers: satisfied, classic, social and obligated. Based on our findings, we offer suggestions for projects to incorporate and manage episodic volunteers, so as to better leverage this type of contributors and potentially improve projects' sustainability. Ann Barcomb, Klaas-Jan Stol, Dirk Riehle, Brian Fitzgerald 0001 |
ICSE | 2 |
| 2019 | Competition-Based Crowdsourcing Software Development: A Multi-Method Study from a Customer PerspectiveabstractCrowdsourcing is emerging as an alternative outsourcing strategy which is gaining increasing attention in the software engineering community. However, crowdsourcing software development involves complex tasks which differ significantly from the micro-tasks that can be found on crowdsourcing platforms such as Amazon Mechanical Turk which are much shorter in duration, are typically very simple, and do not involve any task interdependencies. To achieve the potential benefits of crowdsourcing in the software development context, companies need to understand how this strategy works, and what factors might affect crowd participation. We present a multi-method qualitative and quantitative theory-building research study. First, we derive a set of key concerns from the crowdsourcing literature as an initial analytical framework for an exploratory case study in a Fortune 500 company. We complement the case study findings with an analysis of 13,602 crowdsourcing competitions over a ten-year period on the very popular Topcoder crowdsourcing platform. Drawing from our empirical findings and the crowdsourcing literature, we propose a theoretical model of crowd interest and actual participation in crowdsourcing competitions. We evaluate this model using Structural Equation Modeling. Among the findings are that the level of prize and duration of competitions do not significantly increase crowd interest in competitions. Klaas-Jan Stol, Bora Caglayan, Brian Fitzgerald 0001 |
IEEE Trans. Software Eng. | 1 |
| 2018 | The ABC of Software Engineering ResearchabstractA variety of research methods and techniques are available to SE researchers, and while several overviews exist, there is consistency neither in the research methods covered nor in the terminology used. Furthermore, research is sometimes critically reviewed for characteristics inherent to the methods. We adopt a taxonomy from the social sciences, termed here the ABC framework for SE research, which offers a holistic view of eight archetypal research strategies. ABC refers to the research goal that strives for generalizability over Actors (A) and precise measurement of their Behavior (B), in a realistic Context (C). The ABC framework uses two dimensions widely considered to be key in research design: the level of obtrusiveness of the research and the generalizability of research findings. We discuss metaphors for each strategy and their inherent limitations and potential strengths. We illustrate these research strategies in two key SE domains, global software engineering and requirements engineering, and apply the framework on a sample of 75 articles. Finally, we discuss six ways in which the framework can advance SE research. Klaas-Jan Stol, Brian Fitzgerald 0001 |
ACM Trans. Softw. Eng. Methodol. | 1 |
| 2017 | Introduction to the EASE 2016 special section: Evidence-based software engineering: Past, present, and future
Sarah Beecham, David Bowes, Klaas-Jan Stol |
Inf. Softw. Technol. | 3 |
| 2017 | Continuous software engineering: A roadmap and agenda
Brian Fitzgerald 0001, Klaas-Jan Stol |
J. Syst. Softw. | 2 |
| 2016 | Grounded theory in software engineering research: a critical review and guidelinesabstractGrounded Theory (GT) has proved an extremely useful research approach in several fields including medical sociology, nursing, education and management theory. However, GT is a complex method based on an inductive paradigm that is fundamentally different from the traditional hypothetico-deductive research model. As there are at least three variants of GT, some ostensibly GT research suffers from method slurring, where researchers adopt an arbitrary subset of GT practices that are not recognizable as GT. In this paper, we describe the variants of GT and identify the core set of GT practices. We then analyze the use of grounded theory in software engineering. We carefully and systematically selected 98 articles that mention GT, of which 52 explicitly claim to use GT, with the other 46 using GT techniques only. Only 16 articles provide detailed accounts of their research procedures. We offer guidelines to improve the quality of both conducting and reporting GT studies. The latter is an important extension since current GT guidelines in software engineering do not cover the reporting process, despite good reporting being necessary for evaluating a study and informing subsequent research. Klaas-Jan Stol, Paul Ralph, Brian Fitzgerald 0001 |
ICSE | 1 |
| 2016 | Introduction to the special section - General Theories of Software Engineering: New advances and implications for research
Klaas-Jan Stol, Michael Goedicke, Ivar Jacobson |
Inf. Softw. Technol. | 1 |
| 2015 | The Dos and Dont's of Crowdsourcing Software Development
Brian Fitzgerald 0001, Klaas-Jan Stol |
SOFSEM | 2 |
| 2015 | Theory-oriented software engineering
Klaas-Jan Stol, Brian Fitzgerald 0001 |
Sci. Comput. Program. | 1 |
| 2014 | Two's company, three's a crowd: a case study of crowdsourcing software developmentabstractCrowdsourcing is an emerging and promising approach which involves delegating a variety of tasks to an unknown workforce - the crowd. Crowdsourcing has been applied quite successfully in various contexts from basic tasks on Amazon Mechanical Turk to solving complex industry problems, e.g. InnoCentive. Companies are increasingly using crowdsourcing to accomplish specific software development tasks. However, very little research exists on this specific topic. This paper presents an in-depth industry case study of crowdsourcing software development at a multinational corporation. Our case study highlights a number of challenges that arise when crowdsourcing software development. For example, the crowdsourcing development process is essentially a waterfall model and this must eventually be integrated with the agile approach used by the company. Crowdsourcing works better for specific software development tasks that are less complex and stand-alone without interdependencies. The development cost was much greater than originally expected, overhead in terms of company effort to prepare specifications and answer crowdsourcing community queries was much greater, and the time-scale to complete contests, review submissions and resolve quality issues was significant. Finally, quality issues were pushed later in the lifecycle given the lengthy process necessary to identify and resolve quality issues. Given the emphasis in software engineering on identifying bugs as early as possible, this is quite problematic. Klaas-Jan Stol, Brian Fitzgerald 0001 |
ICSE | 1 |
| 2014 | Inner Source: Coming to a Company Near You Soon!abstractThe nature of software development has changed significantly over the last decade or so, driven by trends such as an increasing level of software outsourcing, distributed development and collaborative development models. One such model of collaborative and distributed development that has attracted significant attention in both industry and research communities is that of Open Source. Open Source development seems to defy traditional wisdom in software development --- with a seeming absence of a predefined process, open source communities have produced high-quality and successful products. Increasingly, large organizations are looking to reproduce such emerging and collaborative development projects by adopting the open source development paradigm within their organizations. This phenomenon is labelled "Inner Source". This talk will present the results of four years of research into Inner Source. Specifically, the talk will address questions such as why companies would want to adopt Inner Source and what factors are important when adopting Inner Source. The talk will draw from several industry cases of Inner Source. Klaas-Jan Stol |
OpenSym | 1 |
| 2014 | Key factors for adopting inner sourceabstractA number of organizations have adopted Open Source Software (OSS) development practices to support or augment their software development processes, a phenomenon frequently referred to as Inner Source . However the adoption of Inner Source is not a straightforward issue. Many organizations are struggling with the question of whether Inner Source is an appropriate approach to software development for them in the first place. This article presents a framework derived from the literature on Inner Source, which identifies nine important factors that need to be considered when implementing Inner Source. The framework can be used as a probing instrument to assess an organization on these nine factors so as to gain an understanding of whether or not Inner Source is suitable. We applied the framework in three case studies at Philips Healthcare, Neopost Technologies, and Rolls-Royce, which are all large organizations that have either adopted Inner Source or were planning to do so. Based on the results presented in this article, we outline directions for future research. Klaas-Jan Stol, Paris Avgeriou, Muhammad Ali Babar 0001, Yan Lucas, Brian Fitzgerald 0001 |
ACM Trans. Softw. Eng. Methodol. | 1 |
| 2013 | Scaling agile methods to regulated environments: an industry case studyabstractAgile development methods are growing in popularity with a recent survey reporting that more than 80% of organizations now following an agile approach. Agile methods were seen initially as best suited to small, co-located teams developing non-critical systems. The first two constraining characteristics (small and co-located teams) have been addressed as research has emerged describing successful agile adoption involving large teams and distributed contexts. However, the applicability of agile methods for developing safety-critical systems in regulated environments has not yet been demonstrated unequivocally, and very little rigorous research exists in this area. Some of the essential characteristics of agile approaches appear to be incompatible with the constraints imposed by regulated environments. In this study we identify these tension points and illustrate through a detailed case study how an agile approach was implemented successfully in a regulated environment. Among the interesting concepts to emerge from the research are the notions of continuous compliance and living traceability. Brian Fitzgerald 0001, Klaas-Jan Stol, Ryan O'Sullivan, Donal O'Brien |
ICSE | 2 |
| 2013 | Balancing Agility and Discipline in a Medical Device Software Organisation
Martin McHugh, Fergal McCaffery, Brian Fitzgerald 0001, Klaas-Jan Stol, Valentine Casey, Garret Coady |
SPICE | 4 |
| 2011 | Design and Evaluation of a Process for Identifying Architecture Patterns in Open Source Software
Klaas-Jan Stol, Paris Avgeriou, Muhammad Ali Babar 0001 |
ECSA | 1 |
| 2011 | A comparative study of challenges in integrating Open Source Software and Inner Source Software
Klaas-Jan Stol, Muhammad Ali Babar 0001, Paris Avgeriou, Brian Fitzgerald 0001 |
Inf. Softw. Technol. | 1 |
| 2010 | Identifying Architectural Patterns Used in Open Source Software: Approaches and Challenges
Klaas-Jan Stol, Paris Avgeriou, Muhammad Ali Babar 0001 |
EASE | 1 |
| 2010 | A systematic review of comparative evidence of aspect-oriented programming
Muhammad Sarmad Ali, Muhammad Ali Babar 0001, Lianping Chen, Klaas-Jan Stol |
Inf. Softw. Technol. | 4 |