This special issue focuses on the difficult problem of how observers and researchers can make sense of how collaborating participants develop a shared understanding both of their task and their own participation in it. Or stated in another way, how can we derive meaning from their emergent and situated meaning making? Meaning making has been studied under a variety of names, and can be conceptualized on different levels of abstraction and from a variety of perspectives. The goal is to attempt to tease apart some of these views, while at the same time seeking means to bring them together in order to provide a more fully elaborated picture. This issue comes with downloadable resources containing the brief video segment which all authors analyzed in the preparation of their contributions.