A sixth-grade class investigated the ecologies of two local retention ponds over the course of one school year. In this context, instruction assisted development as students designed models of the pond in one-gallon jars and attempted to stabilize these jars in sustainable ecosystems that could be used to study questions about the ponds.…

We explore the immediate and longer term consequences of different types of instruction about a central topic in middle school science: the "Control of Variables Strategy" (CVS). CVS represents the procedural and conceptual basis for designing simple, unconfounded experiments, such that unambiguous causal inferences can be made. CVS…