Effort estimation by characterizing developer activity

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.