This chapter examines standard-setting for quality and accountability in the humanitarian sector, specifically the Sphere Project. Prior to standard-setting efforts in the late 1990s, the humanitarian field had weak coordination and standards were set at the organizational level. I show how reflexivity produced new pathways to cooperation and collective action through a critical emotional event. This shared emotional experience created a reflective space at the global level where humanitarian actors convened to collectively address perceived problems in humanitarian activity. This reflective process produced shared understandings and knowledge and consolidated a collective 'we' or community motivated to cooperate and coordinate their activity. The outcome of these processes was a reflective accountability system characterized by three features: collective action, reflective practices, and transformative goals. Instead of eliminating reflection and emotion, standard-setting in the humanitarian sector embedded reflexivity and learning.