@conference {Robles:2014:EDE:2597073.2597107,
	title = {Estimating Development Effort in Free/Open Source Software Projects by Mining Software Repositories: A Case Study of OpenStack},
	booktitle = {Proceedings of the 11th Working Conference on Mining Software Repositories},
	series = {MSR 2014},
	year = {2014},
	pages = {222{\textendash}231},
	publisher = {ACM},
	organization = {ACM},
	address = {New York, NY, USA},
	abstract = {Because of the distributed and collaborative nature of free / open source software (FOSS) projects, the development effort invested in a project is usually unknown, even after the software has been released. However, this information is becoming of major interest, especially ---but not only--- because of the growth in the number of companies for which FOSS has become relevant for their business strategy. In this paper we present a novel approach to estimate effort by considering data from source code management repositories. We apply our model to the OpenStack project, a FOSS project with more than 1,000 authors, in which several tens of companies cooperate. Based on data from its repositories and together with the input from a survey answered by more than 100 developers, we show that the model offers a simple, but sound way of obtaining software development estimations with bounded margins of error.
},
	keywords = {effort estimation, free software, mining software repositories, open source, openstack},
	isbn = {978-1-4503-2863-0},
	doi = {10.1145/2597073.2597107},
	url = {http://doi.acm.org/10.1145/2597073.2597107},
	attachments = {https://flosshub.org/sites/flosshub.org/files/robles_0.pdf},
	author = {Gregorio Robles and Gonz{\'a}lez-Barahona, Jes{\'u}s M. and Cervig{\'o}n, Carlos and Capiluppi, Andrea and Izquierdo-Cort{\'a}zar, Daniel}
}
@conference {Amor:2006:EEC:1139113.1139116,
	title = {Effort Estimation by Characterizing Developer Activity},
	booktitle = {Proceedings of the 2006 International Workshop on Economics Driven Software Engineering Research},
	series = {EDSER {\textquoteright}06},
	year = {2006},
	pages = {3{\textendash}6},
	publisher = {ACM},
	organization = {ACM},
	address = {New York, NY, USA},
	abstract = {During the latest years libre (free, open source) software has gained a lot of attention from the industry. Following this interest, the research community is also studying it. For instance, many teams are performing quantitative analysis on the large quantity of data which is publicly available from the development repositories maintained by libre software projects. However, not much of this research is focused on cost or effort estimations, despite its importance (for instance, for companies developing libre software or collaborating with libre software projects), and the availability of some data which could be useful for this purpose. Our position is that classical effort estimation models can be improved from the study of these data, at least when applied to libre software. In this paper, we focus on the characterization of developer activity, which we argue can improve effort estimation. This activity can be traced with a lot of detail, and the resulting data can also be used for validation of any effort estimation model.
},
	keywords = {developer characterization, effort estimation, mining software repositories, open source software, software economics},
	isbn = {1-59593-396-4},
	doi = {10.1145/1139113.1139116},
	url = {http://doi.acm.org/10.1145/1139113.1139116},
	author = {Amor, Juan Jose and Gregorio Robles and Jesus M. Gonzalez-Barahona}
}
@conference {Robles:2006:GLD:1137983.1138017,
	title = {Geographic location of developers at SourceForge},
	booktitle = {Proceedings of the 2006 international workshop on Mining software repositories},
	series = {MSR {\textquoteright}06},
	year = {2006},
	pages = {144{\textendash}150},
	publisher = {ACM},
	organization = {ACM},
	address = {New York, NY, USA},
	abstract = {The development of libre (free/open source) software is usually performed by geographically distributed teams. Participation in most cases is voluntary, sometimes sporadic, and often not framed by a pre-defined management structure. This means that anybody can contribute, and in principle no national origin has advantages over others, except for the differences in availability and quality of Internet connections and language. However, differences in participation across regions do exist, although there are little studies about them. In this paper we present some data which can be the basis for some of those studies. We have taken the database of users registered at SourceForge, the largest libre software development web-based platform, and have inferred their geographical locations. For this, we have applied several techniques and heuristics on the available data (mainly e-mail addresses and time zones), which are presented and discussed in detail. The results show a snapshot of the regional distribution of SourceForge users, which may be a good proxy of the actual distribution of libre software developers. In addition, the methodology may be of interest for similar studies in other domains, when the available data is similar (as is the case of mailing lists related to software projects).},
	keywords = {distributed, email, email address, free software, geographical location, geography, libre software, mining software repositories, open source software, sourceforge, timezone},
	isbn = {1-59593-397-2},
	doi = {http://doi.acm.org/10.1145/1137983.1138017},
	url = {http://doi.acm.org/10.1145/1137983.1138017},
	attachments = {https://flosshub.org/sites/flosshub.org/files/144GeographicLocation.pdf},
	author = {Gregorio Robles and Jesus M. Gonzalez-Barahona}
}
@conference {Robles:2006:MLS:1137983.1137986,
	title = {Mining large software compilations over time: another perspective of software evolution},
	booktitle = {Proceedings of the 2006 international workshop on Mining software repositories},
	series = {MSR {\textquoteright}06},
	year = {2006},
	pages = {3{\textendash}9},
	publisher = {ACM},
	organization = {ACM},
	address = {New York, NY, USA},
	abstract = {With the success of libre (free, open source) software, a new type of software compilation has become increasingly common. Such compilations, often referred to as {\textquoteright}distributions{\textquoteright}, group hundreds, if not thousands, of software applications and libraries written by independent parties into an integrated system. Software compilations raise a number of questions that have not been targeted so far by software evolution, which usually focuses on the evolution of single applications. Undoubtedly, the challenges that software compilations face differ from those found in single software applications. Nevertheless, it can be assumed that both, the evolution of applications and that of software compilations, have similarities and dependencies.In this sense, we identify a dichotomy, common to that in economics, of software evolution in the small (micro-evolution) and in the large (macro-evolution). The goal of this paper is to study the evolution of a large software compilation, mining the publicly available repository of a well-known Linux distribution, Debian. We will therefore investigate changes related to hundreds of millions of lines of code over seven years. The aspects that will be covered in this paper are size (in terms of number of packages and of number of lines of code), use of programming languages, maintenance of packages and file sizes.},
	keywords = {debian, distributions, evolution, large software collections, lines of code, loc, metrics, mining software repositories, size, sloc, sloccount, software evolution, software integrators},
	isbn = {1-59593-397-2},
	doi = {http://doi.acm.org/10.1145/1137983.1137986},
	url = {http://doi.acm.org/10.1145/1137983.1137986},
	attachments = {https://flosshub.org/sites/flosshub.org/files/3miningLarge.pdf},
	author = {Gregorio Robles and Jesus M. Gonzalez-Barahona and Martin Michlmayr and Amor, Juan Jose}
}
