Midstream modulation is a framework for relating changes in research and innovation to changes in practitioners’ contextual awareness. It is used by the socio-technical integration research (STIR) program to help elucidate and enhance the capacities of laboratory practitioners to participate more deliberately in the governance of science, technology and innovation. STIR involves collaborative inquiry between embedded humanists or social scientists and the scientists, engineers and others who host them. The collaborative inquiry takes place during routine research and innovation activities, generating feedback that can modulate these activities in real-time. Reflexive midstream modulations can disrupt and enhance the conditions under which research and innovation practitioners engage the social and ethical contexts of their work. This chapter presents the conceptual backbone and the overall philosophy behind midstream modulation, and surveys the concrete outcomes that typically result from laboratory engagement studies.