When using an argument based inquiry approach like the Science Writing Heuristic (SWH) approach, argumentation between peers and with a teacher will provide great opportunities for students to experience negotiation of meaning in relation to science content. However, students do not automatically engage in dialogue and argumentation with classmates about the science content. Therefore, teachers need to model proper discourse patterns for students to follow. These patterns included active listening, respect for different points of view, and thoughtful justification for their ideas. This article describes learning conditions that promote negotiation in science in order to help teachers support students' argumentation. (Contains 2 tables and 1 figure.)