@conference {Vasilescu:2016:SLM:2884781.2884875,
	title = {The Sky is Not the Limit: Multitasking Across GitHub Projects},
	booktitle = {Proceedings of the 38th International Conference on Software Engineering (ICSE 2016)},
	series = {ICSE {\textquoteright}16},
	year = {2016},
	pages = {994{\textendash}1005},
	publisher = {ACM},
	organization = {ACM},
	address = {New York, NY, USA},
	abstract = {Software development has always inherently required multitasking: developers switch between coding, reviewing, testing, designing, and meeting with colleagues. The advent of software ecosystems like GitHub has enabled something new: the ability to easily switch between projects. Developers also have social incentives to contribute to many projects; prolific contributors gain social recognition and (eventually) economic rewards. Multitasking, however, comes at a cognitive cost: frequent context-switches can lead to distraction, sub-standard work, and even greater stress. In this paper, we gather ecosystem-level data on a group of programmers working on a large collection of projects. We develop models and methods for measuring the rate and breadth of a developers{\textquoteright} context-switching behavior, and we study how context-switching affects their productivity. We also survey developers to understand the reasons for and perceptions of multitasking. We find that the most common reason for multitasking is interrelationships and dependencies between projects. Notably, we find that the rate of switching and breadth (number of projects) of a developer{\textquoteright}s work matter. Developers who work on many projects have higher productivity if they focus on few projects per day. Developers that switch projects too much during the course of a day have lower productivity as they work on more projects overall. Despite these findings, developers perceptions of the benefits of multitasking are varied.
},
	keywords = {github, multitasking, productivity},
	isbn = {978-1-4503-3900-1},
	doi = {10.1145/2884781.2884875},
	url = {http://doi.acm.org/10.1145/2884781.2884875},
	author = {Vasilescu, Bogdan and Blincoe, Kelly and Xuan, Qi and Casalnuovo, Casey and Damian, Daniela and Devanbu, Premkumar and Filkov, Vladimir}
}
@proceedings {1762,
	title = {A Data Set for Social Diversity Studies of GitHub Teams},
	year = {2015},
	month = {05/2015},
	publisher = {IEEE},
	abstract = {Like any other team oriented activity, the software
development process is effected by social diversity in the programmer
teams. The effect of team diversity can be significant,
but also complex, especially in decentralized teams. Discerning
the precise contribution of diversity on teams{\textquoteright} effectiveness
requires quantitative studies of large data sets.
Here we present for the first time a large data set of social
diversity attributes of programmers in GITHUB teams. Using
alias resolution, location data, and gender inference techniques,
we collected a team social diversity data set of 23,493 GITHUB
projects. We illustrate how the data set can be used in practice
with a series of case studies, and we hope its availability will foster
more interest in studying diversity issues in software teams.},
	keywords = {ghtorrent, github},
	url = {http://www.win.tue.nl/~aserebre/cr-msr-data-15.pdf},
	attachments = {https://flosshub.org/sites/flosshub.org/files/cr-msr-data-15.pdf},
	author = {Vasilescu, Bogdan and Serebrenik, Alexander and Filkov, Vladimir}
}
@proceedings {1713,
	title = {Gender and Tenure Diversity in GitHub Teams},
	year = {2015},
	abstract = {Software development is usually a collaborative venture.
Open Source Software (OSS) projects are no exception; indeed,
by design, the OSS approach can accommodate teams
that are more open, geographically distributed, and dynamic
than commercial teams. This, we find, leads to OSS teams
that are quite diverse. Team diversity, predominantly in of-
fline groups, is known to correlate with team output, mostly
with positive effects. How about in OSS?
Using GITHUB, the largest publicly available collection of
OSS projects, we studied how gender and tenure diversity
relate to team productivity and turnover. Using regression
modeling of GITHUB data and the results of a survey, we
show that both gender and tenure diversity are positive and
significant predictors of productivity, together explaining a
sizable fraction of the data variability. These results can
inform decision making on all levels, leading to better outcomes
in recruiting and performance.},
	keywords = {gender, github, team},
	url = {http://bvasiles.github.io/papers/chi15.pdf},
	attachments = {https://flosshub.org/sites/flosshub.org/files/chi15.pdf},
	author = {Vasilescu, Bogdan and Posnett, Daryl and Ray, Baishakhi and van den Brand, Mark G.J. and Serebrenik, Alexander and Devanbu, Premkumar and Filkov, Vladimir}
}
@proceedings {1766,
	title = {Wait For It: Determinants of Pull Request Evaluation Latency on GitHub},
	year = {2015},
	month = {05/2015},
	publisher = {IEEE},
	abstract = {The pull-based development model, enabled by git
and popularised by collaborative coding platforms like BitBucket,
Gitorius, and GitHub, is widely used in distributed software
teams. While this model lowers the barrier to entry for potential
contributors (since anyone can submit pull requests to any repository),
it also increases the burden on integrators (i.e., members
of a project{\textquoteright}s core team, responsible for evaluating the proposed
changes and integrating them into the main development line),
who struggle to keep up with the volume of incoming pull
requests. In this paper we report on a quantitative study that tries
to resolve which factors affect pull request evaluation latency
in GitHub. Using regression modeling on data extracted from
a sample of GitHub projects using the Travis-CI continuous
integration service, we find that latency is a complex issue,
requiring many independent variables to explain adequately.},
	url = {https://bvasiles.github.io/papers/msr15.pdf},
	attachments = {https://flosshub.org/sites/flosshub.org/files/msr15.pdf},
	author = {Yu, Yue and Wang, Huaimin and Filkov, Vladimir and Devanbu, Premkumar and Vasilescu, Bogdan}
}
@conference {Vasilescu:2014:SQS:2531602.2531659,
	title = {How Social Q\&A Sites Are Changing Knowledge Sharing in Open Source Software Communities},
	booktitle = {Proceedings of the 17th ACM Conference on Computer Supported Cooperative Work \&\#38; Social Computing},
	series = {CSCW {\textquoteright}14},
	year = {2014},
	pages = {342{\textendash}354},
	publisher = {ACM},
	organization = {ACM},
	address = {New York, NY, USA},
	abstract = {Historically, mailing lists have been the preferred means for coordinating development and user support activities. With the emergence and popularity growth of social Q\&A sites such as the StackExchange network (e.g., StackOverflow), this is beginning to change. Such sites offer different socio-technical incentives to their participants than mailing lists do, e.g., rich web environments to store and manage content collaboratively, or a place to showcase their knowledge and expertise more vividly to peers or potential recruiters. A key difference between StackExchange and mailing lists is gamification, i.e., StackExchange participants compete to obtain reputation points and badges. In this paper, we use a case study of R (a widely-used tool for data analysis) to investigate how mailing list participation has evolved since the launch of StackExchange. Our main contribution is the assembly of a joint data set from the two sources, in which participants in both the texttt{r-help} mailing list and StackExchange are identifiable. This permits their activities to be linked across the two resources and also over time. With this data set we found that user support activities show a strong shift away from texttt{r-help}. In particular, mailing list experts are migrating to StackExchange, where their behaviour is different. First, participants active both on texttt{r-help} and on StackExchange are more active than those who focus exclusively on only one of the two. Second, they provide faster answers on StackExchange than on texttt{r-help}, suggesting they are motivated by the emph{gamified} environment. To our knowledge, our study is the first to directly chart the changes in behaviour of specific contributors as they migrate into gamified environments, and has important implications for knowledge management in software engineering.},
	keywords = {a, crowdsourced knowledge, gamification., mailing lists, open source, social q\&\#38},
	isbn = {978-1-4503-2540-0},
	doi = {10.1145/2531602.2531659},
	url = {http://doi.acm.org/10.1145/2531602.2531659},
	attachments = {https://flosshub.org/sites/flosshub.org/files/cscw14.pdf},
	author = {Vasilescu, Bogdan and Serebrenik, Alexander and Devanbu, Prem and Filkov, Vladimir}
}
@conference {969,
	title = {Validity of network analyses in Open Source Projects},
	booktitle = {2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010)2010 7th IEEE Working Conference on Mining Software Repositories (MSR 2010)},
	year = {2010},
	note = {"We have mined archival records of developer mailing lists to generate reply-to social networks for the three OSS projects: Apache, MySQL, and Perl."

"For each of these projects, we construct an information flow network based on messages that are sent as replies to previous messages....We use this methodology on all mined data to create a network of mailing list participants. "},
	pages = {201 - 209},
	publisher = {IEEE},
	organization = {IEEE},
	address = {Cape Town, South Africa},
	abstract = {Social network methods are frequently used to analyze networks derived from Open Source Project communication and collaboration data. Such studies typically discover patterns in the information flow between contributors or contributions in these projects. Social network metrics have also been used to predict defect occurrence. However, such studies often ignore or side-step the issue of whether (and in what way) the metrics and networks of study are influenced by inadequate or missing data. In previous studies email archives of OSS projects have provided a useful trace of the communication and co-ordination activities of the participants. These traces have been used to construct social networks that are then subject to various types of analysis. However, during the construction of these networks, some assumptions are made, that may not always hold; this leads to incomplete, and sometimes incorrect networks. The question then becomes, do these errors affect the validity of the ensuing analysis? In this paper we specifically examine the stability of network metrics in the presence of inadequate and missing data. The issues that we study are: 1) the effect of paths with broken information flow (i.e. consecutive edges which are out of temporal order) on measures of centrality of nodes in the network, and 2) the effect of missing links on such measures. We demonstrate on three different OSS projects that while these issues do change network topology, the metrics used in the analysis are stable with respect to such changes.},
	keywords = {apache, email archives, mailing lists, missing data, mysql, perl, social networks},
	isbn = {978-1-4244-6802-7},
	doi = {10.1109/MSR.2010.5463342},
	attachments = {https://flosshub.org/sites/flosshub.org/files/201NetworkAnalysis.pdf},
	author = {Nia, Roozbeh and Christian Bird and Devanbu, Premkumar and Filkov, Vladimir}
}
@conference {bird2008lss,
	title = {{Latent Social Structure in Open Source Projects}},
	booktitle = {SIGSOFT {\textquoteright}08/FSE-16: Proceedings of the 16th ACM SIGSOFT Symposium on Foundations of Software Engineering},
	year = {2008},
	note = {We first identified the projects of interest and mined the developer mailing list archives and source code repositories of each of the projects. Next, we filtered the mailing list messages and created a social network of the participants over 3-month intervals. We then calculated the community structure of each social network. Following that, the relevance of the divisions of participants was evaluated quantitatively using mined source code development data and qualitatively by manual methods.},
	pages = {24{\textendash}35},
	publisher = {ACM},
	organization = {ACM},
	abstract = {Commercial software project managers design project organizational structure carefully, mindful of available skills, division of labour, geographical boundaries, etc. These organizational {\textquotedblleft}cathedrals{\textquotedblright} are to be contrasted with the "bazaar-like" nature of Open Source Software (OSS) Projects, which have no pre-designed organizational structure. Any structure that exists is dynamic, self-organizing, latent, and usually not explicitly stated. Still, in large, complex, successful, OSS projects, we do expect that subcommunities will form spontaneously within the developer teams. Studying these subcommunities, and their behavior can shed light on how successful OSS projects self-organize. This phenomenon could well hold important lessons for how commercial software teams might be organized. Building on known well-established techniques for detecting community structure in complex networks, we extract and study latent subcommunities from the email social network of several projects: Apache HTTPD, Python, PostgresSQL, Perl, and Apache ANT. We then validate them with software development activity history. Our results show that subcommunities do indeed spontaneously arise within these projects as the projects evolve. These subcommunities manifest most strongly in technical discussions, and are significantly connected with collaboration behaviour.},
	attachments = {https://flosshub.org/sites/flosshub.org/files/bird2008lss.pdf},
	author = {Christian Bird and David Pattison and Raissa D{\textquoteright}Souza and Filkov, Vladimir and Devanbu, Premkumar}
}
