Collaboration has become an integral part of software engineering. The widespread availability and adoption of social channels has led to a culture where developers participate and collaborate more frequently with one another. While collaboration in software engineering has been studied extensively, models and frameworks do not adequately capture how development team members “regulate” themselves, one another, and their projects. I borrow the term “regulate” from the learning sciences to refer to mindful processes developers engage in to determine what tasks they need to complete and who should be involved, what their goals are relative to those tasks, how they should meet their goals, what domain knowledge needs to be manipulated, and why they use a particular approach or tool. This research starts by borrowing constructs from the theory of regulated learning in the learning science domain, adapting and extending them as a model of collaboration for software engineering: the Model of Regulation. This model was composed to capture how individuals self-regulate their tasks, knowledge and motivation, how they regulate one another, and how they achieve a shared understanding of project goals and required tasks. The model provides a vocabulary for comparing and analyzing collaboration tools and processes. In this thesis, I present the Model of Regulation as a new and complementary theoretical model of collaboration for software engineering and showcase its potential by using the model to analyze features of a collaborative tool, gain insights into an open-source software development community and to create an instrument that investigates about collaboration practices and tool support in units of collaboration (e.g., group, project, community). / Graduate