Competence committees are groups of educators that monitor the progress of medical trainees and decide when they should be promoted to the next stage of training. They represent an important part of modern-day competency-based medical education programs, yet relatively little is known about their implementation and decision-making practices. This thesis seeks to fill a critical gap in the literature by generating empirical evidence with respect to competence committee implementation and decision-making practices across multiple programs. The first data chapter uses a multi-method approach to examine competence committee implementation practices at a Canadian institution over a three-year period. The second and third chapters examine how individuals and groups make promotion decisions, respectively. These chapters also consider the role of non-traditional data sources, such as anecdotal evidence, in competence committees’ decision-making processes. The final data chapter considers the role of social influences and power and examines how factors such as members’ position on the committee, gender, and race/ethnicity influence their contributions to the committee. This thesis provides insight into some of the challenges that exist with respect to competence committee implementation and offers potential solutions based on best practices across multiple programs. It also highlights factors that can influence competence committee decision making and discusses ways that their decision-making processes can be optimized. Broader implications of this thesis, including the role of groups in solving complex problems and the importance of diversity (both in terms of demographics and functional specialization) in ensuring good decision-making outcomes, are also discussed. / Thesis / Doctor of Philosophy (PhD) / Competence committees are groups of experienced health professionals and educators whose job is to determine whether physician learners (i.e., residents) are ready to progress to the next stage of training and responsibility. These committees are relatively new, and as a result, we do not know very much about how they make decisions. Given the importance of competence committees in ensuring that physicians are able to provide high-quality and safe patient care, the purpose of this thesis was to examine competence committee implementation and decision-making practices at a Canadian academic centre. This took place in two parts. First, we studied competence committees over a three-year period using surveys, interviews, and observations. This helped us understand some of their benefits and challenges. Next, we conducted a series of experiments to understand how competence committee members make decisions both individually and as part of a group. These experiments also helped us understand how competence committees make sense of different types of data, such as prior knowledge about a resident or their assessors. Finally, we examined how various aspects of members’ social identities, such as their position on the committee, their gender, and their race/ethnicity, influence their contributions to the committee. Collectively, the findings of this thesis help to advance the scientific literature in the areas of medical education and group decision making. They can also be used to optimize competence committee operations, which can in turn positively impact patients, healthcare, and society.