%0 Conference Paper %B Proceedings of the 11th Working Conference on Mining Software Repositories %D 2014 %T The Promises and Perils of Mining GitHub %A Kalliamvakou, Eirini %A Gousios, Georgios %A Blincoe, Kelly %A Singer, Leif %A Daniel M. German %A Damian, Daniela %K bias %K code reviews %K git %K github %K mining software repositories %X 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 GitHub's 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 GitHub's 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. %B Proceedings of the 11th Working Conference on Mining Software Repositories %S MSR 2014 %I ACM %C New York, NY, USA %P 92–101 %@ 978-1-4503-2863-0 %U http://doi.acm.org/10.1145/2597073.2597074 %R 10.1145/2597073.2597074 %> https://flosshub.org/sites/flosshub.org/files/perils.pdf %0 Conference Paper %B Proceedings of the 11th Working Conference on Mining Software Repositories %D 2014 %T Understanding "Watchers" on GitHub %A Sheoran, Jyoti %A Blincoe, Kelly %A Kalliamvakou, Eirini %A Damian, Daniela %A Ell, Jordan %K github %K mining challenge %K msr challenge %K repositories %K Software Teams %K Watchers %X Users on GitHub can watch repositories to receive notifications about project activity. This introduces a new type of passive project membership. In this paper, we investigate the behavior of watchers and their contribution to the projects they watch. We find that a subset of project watchers begin contributing to the project and those contributors account for a significant percentage of contributors on the project. As contributors, watchers are more confident and contribute over a longer period of time in a more varied way than other contributors. This is likely attributable to the knowledge gained through project notifications. %B Proceedings of the 11th Working Conference on Mining Software Repositories %S MSR 2014 %I ACM %C New York, NY, USA %P 336–339 %@ 978-1-4503-2863-0 %U http://doi.acm.org/10.1145/2597073.2597114 %R 10.1145/2597073.2597114