This study investigated teacher-child interaction within small-group science activities in a fourth-grade classroom. This qualitative study revealed three "zones of interaction," or teacher-child interaction categories: Individual Zones of Interaction, Multiple Zones of Interaction, and a Collective Zone of Interaction. Each zone was further shaped by either a procedural, conceptual, or managerial focus for the interaction. These zones granted children differential levels of access to the teacher's knowledge. Based on these data and findings, we propose a discourse model for elementary science classrooms that encompasses talk, materials, knowledge, engagement, and power.