This study investigates how students who are peripherally positioned in computer science-based, collaborative group work meaningfully engage with the group activity in order to learn. Our research took place in the context of a one-day, all-girl robotics workshop. This work proceeds from the premise that learning about programming is mediated most directly by interaction with the robotics materials. In this and other studies of robotics, we have observed group negotiations over who would control materials at any given time. In our investigation of these negotiations, and the student participation that results, we have noticed that some students appear to be able to assert an agentic identity from the periphery, while other students struggle to participate. It is this phenomenon that we explore. A total of 17 girls participated in the workshop. In this study, we focus on two students from different groups who had less direct contact with the materials, and were thus positioned peripherally. We analyze discourse patterns to characterize the engagement of both the two groups of which the students were a part, as well as the two students themselves. One of the groups demonstrated stronger coordination from a discourse perspective and the focal student in that group exhibited meaningful engagement, while the other group demonstrated weaker coordination from a discourse perspective and the focal student exhibited marginal engagement. This contrast allows us to begin to build a picture of the factors that support learning from the periphery. Our results indicate that agency exhibited in well-coordinated group discussions is a key aspect of meaningful engagement. [For a related journal article from the authors, see EJ1121710.]