In this article, we examine the relationship between how students are positioned in social encounters and how this influences learning in a technology-supported science project. We pursue this topic by focusing on the participation trajectory of one particular learner. The analysis shows that the student cannot be interpreted as one type of student having only one type of identity as a learner. His position as a learner shifts multiple times during the instructional trajectory. We discuss the different consequences that this has on the student's participation and learning of science.