Reasoning about data in middle school science

This case study illustrates instruction in an urban 6th-grade classroom in which students were learning about mass, volume, and density by attempting to layer (stack) three miscible solutions with differing densities atop one another. The study examines classroom discourse and interaction on the basis of four teaching goals: (a) reaching consensus about which stacks were possible, (b) developing persuasive arguments that separated data from noise, (c) establishing social norms for collective inquiry, and (d) appreciating the epistemological status of scientific knowledge. The study traces the fate of three stacks that students claimed were possible after initial investigations with the solutions. These claims underwent a process of collective validation in which consensus without coercion was the goal, which illustrates emergent standards for backing claims with evidence, as well as for replicability, among the students. Students were successful in achieving three of the four goals, with some qualifications. In relation to Goal 3, which required generalization to other situations, somewhat less success is reported. Limitations in the current standards, difficulties of time allotment in current curricula, and establishing classroom cultures of inquiry are discussed. © 1999 John Wiley & Sons, Inc. J Res Sci Teach 36: 179–199, 1999