Knowledge of scientific models and their uses is a concept that has become a key benchmark in many of the science standards of the past 30 years, including the proposed Next Generation Science Standards. Knowledge of models is linked to other important nature of science concepts such as theory change which are also rising in prominence in newer…

Child development involves the process of mastering cultural tools, which modify relations with the world and provide the means to act on the self. A sign is a universal cultural tool, but these tools are not the same for all ages. The problem of specifying development becomes one of finding the tools that children use in their activity.…

The authors explore how children's play can support the development of the foundations of mathematics learning and how adults can support children's representation of--and thus the "mathematization" of--their play. The authors review research about the amount and nature of mathematics found in the free play of children. They briefly…