Creating, visualizing, and critiquing data are integral knowledge‐building practices within science, as well as many other fields. Yet data is often treated as neutral and value‐free, perpetuating narratives of science as a dispassionate discipline where data are merely extracted, repackaged, and distributed anew. As researchers and educators seek to imagine, design and support more humanistic accounts of young people's data practices, attuning to emotion will be a key area for further study. Recent scholarship in science education has elevated emotion as inseparable from disciplinary knowledge‐building practices, yet studies of emotion emergent within young people's data practices remain less understood. As part of the special issue Centering Affect and Emotion Toward Justice and Dignity in Science Education, this article explores how emotion and data are co‐produced as children construct and critique data visualizations together, collectively transforming notes, tallies and sketches into class‐level aggregated data displays within a fifth grade ecology curriculum. Analyzing interviews, classroom video recordings, and newly constructed data visualizations, I reveal how feeling, sensemaking and practice are entangled as children and their classmates build a paper data map and a dot plot graph, shaped by personal, cultural and sociopolitical dimensions. I show how these emergent emotional configurations shift activity from collaborative to competitive, in turn changing attention to the data itself (properties, histories, visualizations), the underlying organisms being studied and the ecological system‐level interactions. I argue that as science and data science education push forward a zeal for data, it will be important to attune to the emotional and relational dimensions that undergird children's emergent data practices.
