@proceedings {1912, title = {Developer Turnover in Global, Industrial Open Source Projects: Insights from Applying Survival Analysis}, year = {2017}, note = {we study five industrial OSS projects of different sizes (in terms of software size, contributors and number of companies involved) and examine whether the duration of developers staying in a project is related to following four factors: (i) the time of first contribution, (ii) the rate of maintaining own files, (iii) the main action type, and (iv) the main job type projects: WikiMedia, OpenStack, GlusterFS from Red Hat, Xen Project from the Linux Foundation and Apache CloudStack}, month = {05/2017}, pages = {66-75}, abstract = {Large open source software projects often have a globally distributed development team. Studies have shown developer turnover has a significant impact on the project success. Frequent developer turnover may lead to loss of productivity due to lacking relevant knowledge and spending extra time learning how projects work. Thus, lots of attention has been paid to which factors are related to developer retention; however, few of them focus on the impact of activities of individual developers. In this paper, we study five open source projects from different organizations and examine whether developer turnover is affected by when they start contributing and what types of contributions they are making. Our study reveals that developers have higher chances to survive in software projects when they 1) start contributing to the project earlier; 2) mainly modify instead of creating files; 3) mainly code instead of dealing with documentations. Our results also shed lights on the potential approaches to improving developer retention.}, keywords = {survival analysis}, author = {Bin Lin and Gregorio Robles and Serebrenik, Alexander} } @proceedings {1458, title = {Do More Experienced Developers Introduce Fewer Bugs?}, volume = {378}, year = {2012}, note = {"Some Mozilla Foundation projects have been the selected case of study for this paper. The analysis is based on the Mercurial repository which offers a list of repositories that can be easily cloned. As a summary, 19 projects were analyzed, with more than 100,000 commits, more than 2,500 authors and around 4 years of history up to June 2011."}, month = {09/2012}, pages = {268-273}, publisher = {IFIP AICT, Springer}, abstract = {Developer experience is a common matter of study in the software maintenance and evolution research literature. However it is still not well understood if less experienced developers are more prone to introduce errors in the source code than their more experienced colleagues. This paper aims to study the relationships between experience and the bug introduction ratio using the Mozilla community as case of study. As results, statistical differences among developers with different levels of experience has not been observed, when the expected result would have been the opposite1.}, keywords = {mercurial, mozilla, scm, source code analysis}, author = {Izquierdo-Cort{\'a}zar, Daniel and Gregorio Robles and Gonz{\'a}lez-Barahona, Jes{\'u}s M.} } @conference {970, title = {Determinism and evolution}, booktitle = {Proceedings of the 2008 international workshop on Mining software repositories - MSR {\textquoteright}08}, year = {2008}, month = {05/2008}, pages = {1-9}, publisher = {ACM Press}, organization = {ACM Press}, address = {New York, New York, USA}, abstract = {It has been proposed that software evolution follows a Self-Organized Criticality (SOC) dynamics. This fact is supported by the presence of long range correlations in the time series of the number of changes made to the source code over time. Those long range correlations imply that the current state of the project was determined time ago. In other words, the evolution of the software project is governed by a sort of determinism. But this idea seems to contradict intuition. To explore this apparent contradiction, we have performed an empirical study on a sample of 3,821 libre (free, open source) software projects, finding that their evolution projects is short range correlated. This suggests that the dynamics of software evolution may not be SOC, and therefore that the past of a project does not determine its future except for relatively short periods of time, at least for libre software.}, keywords = {changes, evolution, source code, sourceforge}, isbn = {9781605580241}, doi = {10.1145/1370750.1370752}, attachments = {https://flosshub.org/sites/flosshub.org/files/p1-herraiz.pdf}, author = {Gonz{\'a}lez-Barahona, Jes{\'u}s M. and Gregorio Robles and Herraiz, Israel} } @conference {Robles:2005:DIM:1083142.1083162, title = {Developer identification methods for integrated data from various sources}, booktitle = {Proceedings of the 2005 international workshop on Mining software repositories}, series = {MSR {\textquoteright}05}, year = {2005}, pages = {106-110}, publisher = {ACM}, organization = {ACM}, address = {New York, NY, USA}, abstract = {Studying a software project by mining data from a single repository has been a very active research field in software engineering during the last years. However, few efforts have been devoted to perform studies by integrating data from various repositories, with different kinds of information, which would, for instance, track the different activities of developers. One of the main problems of these multi-repository studies is the different identities that developers use when they interact with different tools in different contexts. This makes them appear as different entities when data is mined from different repositories (and in some cases, even from a single one). In this paper we propose an approach, based on the application of heuristics, to identify the many identities of developers in such cases, and a data structure for allowing both the anonymized distribution of information, and the tracking of identities for verification purposes. The methodology will be presented in general, and applied to the GNOME project as a case example. Privacy issues and partial merging with new data sources will also be considered and discussed.}, keywords = {anonymization, bug tracker, developers, email, email address, gnome, identity, mailing list, privacy, source code, version control}, isbn = {1-59593-123-6}, doi = {http://doi.acm.org/10.1145/1082983.1083162}, url = {http://doi.acm.org/10.1145/1082983.1083162}, attachments = {https://flosshub.org/sites/flosshub.org/files/106DeveloperIdentification.pdf}, author = {Gregorio Robles and Jesus M. Gonzalez-Barahona} }