Leif Singer

The promises and perils of mining GitHub

With over 10 million git repositories, GitHub is becoming one of the most important source of software artifacts on the Internet. Researchers are starting to mine the information stored in GitHubs event logs, trying to understand how its users employ the site to collaborate on software. However, so far there have been no studies describing the quality and properties of the data available from GitHub. We document the results of an empirical study aimed at understanding the characteristics of the repositories in GitHub and how users take advantage of GitHubs main features---namely commits, pull requests, and issues. Our results indicate that, while GitHub is a rich source of data on software development, mining GitHub for research purposes should take various potential perils into consideration. We show, for example, that the majority of the projects are personal and inactive; that GitHub is also being used for free storage and as a Web hosting service; and that almost 40% of all pull requests do not appear as merged, even though they were. We provide a set of recommendations for software engineering researchers on how to approach the data in GitHub.

The (R) Evolution of social media in software engineering

Software developers rely on media to communicate, learn, collaborate, and coordinate with others. Recently, social media has dramatically changed the landscape of software engineering, challenging some old assumptions about how developers learn and work with one another. We see the rise of the social programmer who actively participates in online communities and openly contributes to the creation of a large body of crowdsourced socio-technical content. In this paper, we examine the past, present, and future roles of social media in software engineering. We provide a review of research that examines the use of different media channels in software engineering from 1968 to the present day. We also provide preliminary results from a large survey with developers that actively use social media to understand how they communicate and collaborate, and to gain insights into the challenges they face. We find that while this particular population values social media, traditional channels, such as face-to-face communication, are still considered crucial. We synthesize findings from our historical review and survey to propose a roadmap for future research on this topic. Finally, we discuss implications for research methods as we argue that social media is poised to bring about a paradigm shift in software engineering research.

Software engineering at the speed of light: how developers stay current using twitter

The microblogging service Twitter has over 500 million users posting over 500 million tweets daily. Research has established that software developers use Twitter in their work, but this has not yet been examined in detail. Twitter is an important medium in some software engineering circles—understanding its use could lead to improved support, and learning more about the reasons for non-adoption could inform the design of improved tools. In a qualitative study, we surveyed 271 and interviewed 27 developers active on GitHub. We find that Twitter helps them keep up with the fast-paced development landscape. They use it to stay aware of industry changes, for learning, and for building relationships. We discover the challenges they experience and extract their coping strategies. Some developers do not want to or cannot embrace Twitter for their work—we show their reasons and alternative channels. We validate our findings in a follow-up survey with more than 1,200 respondents.

It was a bit of a race: gamification of version control

The adoption of software engineering practices cannot always be achieved by education or processes. However, social software has the potential for supporting deliberate behavior change. We present preliminary results of an experiment in which we encouraged computer science students to make more frequent commits to version control by using a social software application. We provided a web-based newsfeed of commits that also displayed a leaderboard. While we have yet to analyze the data, interviews we conducted with the participants allow for first qualitative insights.

Mutual assessment in the social programmer ecosystem: an empirical investigation of developer profile aggregators

The multitude of social media channels that programmers can use to participate in software development has given rise to online developer profiles that aggregate activity across many services. Studying members of such developer profile aggregators, we found an ecosystem that revolves around the social programmer. Developers are assessing each other to evaluate whether other developers are interesting, worth following, or worth collaborating with. They are self-conscious about being assessed, and thus manage their public images. They value passion for software development, new technologies, and learning. Some recruiters participate in the ecosystem and use it to find candidates for hiring; other recruiters struggle with the interpretation of signals and issues of trust. This mutual assessment is changing how software engineers collaborate and how they advance their skills.

An in-depth study of the promises and perils of mining GitHub

With over 10 million git repositories, GitHub is becoming one of the most important sources of software artifacts on the Internet. Researchers mine the information stored in GitHub’s event logs to understand how its users employ the site to collaborate on software, but so far there have been no studies describing the quality and properties of the available GitHub data. We document the results of an empirical study aimed at understanding the characteristics of the repositories and users in GitHub; we see how users take advantage of GitHub’s main features and how their activity is tracked on GitHub and related datasets to point out misalignment between the real and mined data. Our results indicate that while GitHub is a rich source of data on software development, mining GitHub for research purposes should take various potential perils into consideration. For example, we show that the majority of the projects are personal and inactive, and that almost 40 % of all pull requests do not appear as merged even though they were. Also, approximately half of GitHub’s registered users do not have public activity, while the activity of GitHub users in repositories is not always easy to pinpoint. We use our identified perils to see if they can pose validity threats; we review selected papers from the MSR 2014 Mining Challenge and see if there are potential impacts to consider. We provide a set of recommendations for software engineering researchers on how to approach the data in GitHub.

How Social and Communication Channels Shape and Challenge a Participatory Culture in Software Development

Software developers use many different communication tools and channels in their work. The diversity of these tools has dramatically increased over the past decade and developers now have access to a wide range of socially enabled communication channels and social media to support their activities. The availability of such social tools is leading to a participatory culture of software development, where developers want to engage with, learn from, and co-create software with other developers. However, the interplay of these social channels, as well as the opportunities and challenges they may create when used together within this participatory development culture are not yet well understood. In this paper, we report on a large-scale survey conducted with 1,449 GitHub users. We discuss the channels these developers find essential to their work and gain an understanding of the challenges they face using them. Our findings lay the empirical foundation for providing recommendations to developers and tool designers on how to use and improve tools for software developers.

A Simple Algorithm for Automatic Layout of BPMN Processes

Badly and inconsistently layouted business processes are hard to read for humans and therefore lack comprehensibility. Furthermore, processes generated by software have no layout at all. If stakeholders cannot comprehend the process descriptions, they are unable to validate them and ¿nd mistakes. By offering a fully automatic layout algorithm for BPMN, it is possible to layout business processes in a consistent and clear way so that stakeholders can better and quicker comprehend the contents. This leads to better comprehensiblity and thus to better communication in BPM / SOA projects and allows for consistent process layouts throughout projects and enterprises - independent from the model source. In addition, this permits using generated models without manual layouting.

Using popular social network sites to support requirements elicitation, prioritization and negotiation

Social networks have changed our daily life and they have the potential to significantly influence and support Requirements Engineering (RE) activities. Social network-based RE approaches will allow us to overcome limitations of traditional approaches and allow end users to play a more prominent role in RE. They are key stakeholders in many software projects. However, involving end users is challenging, particularly when they are not within organizational reach. The goal of our work is to increase end user involvement in RE. In this paper we present an approach where we harness a social network to perform RE activities such as elicitation, prioritization and negotiation. Our approach was applied in three studies where students used Facebook to actively participate in RE activities of different projects. Although there are limitations, the results show that a popular social network site can support distributed RE.

A study of innovation diffusion through link sharing on stack overflow

It is poorly understood how developers discover and adopt software development innovations such as tools, libraries, frameworks, or web sites that support developers. Yet, being aware of and choosing appropriate tools and components can have a significant impact on the outcome of a software project. In our study, we investigate link sharing on Stack Overflow to gain insights into how software developers discover and disseminate innovations. We find that link sharing is a significant phenomenon on Stack Overflow, that Stack Overflow is an important resource for software development innovation dissemination and that its part of a larger interconnected network of online resources used and referenced by developers. This knowledge can guide researchers and practitioners who build tools and services that support software developers in the exploration, discovery, and adoption of software development innovations.