As you may be aware, Developing and Using Models is profiled as one of the NGSS Science and Engineering Practices. Like the other dimensions, it is presented as a sequential skill set that expands in coverage and increases in sophistication as we move upwards through the grade bands, building upon previous cached knowledge.
Models for Young Students
In kindergarten through grade 2, the concept of scientific and engineering models reflects more of a static representation of a natural-world concept. At this level, it is not essential to incorporate dynamics into a behavioral aspect of the model; that comes later. At the K–2 band, we are more interested in the representations of events and design solutions. Therefore, diagrams and drawings remain quite valid as communication devices, as do physical replicas. The exploitation of storyboards is also a powerful tool in displaying the elements of a sequential event. Even the old shoebox diorama retains its role as a communicator of structure or events.
However, when afforded the opportunity, students should be encouraged to build additional understanding through the analysis of their model. For example, suppose they have constructed that familiar solar system model. Even with its out-of-scale representations, it is a viable landscape on which to make predictions. Children can be challenged to predict and draw inferences on how a relative distance to the sun impacts a planet’s climate. Based upon observations of their model, will the inner planets be warmer or colder? But of even greater importance is why? As you can see, the model’s role rises to something more than a finished piece of art that hangs from the ceiling and assumes the role of conceptual landscape.
How Models Evolve as Students Get Older
As students move through the grade bands, the concept of model evolves in sophistication so that it integrates more of the dynamics of a system whose inputs impact outcome. For example, in constructing a model of osmotic pressure that affects a cell’s volume, you produce a functional classroom model that mirrors real-world physical behavior driven by diffusion. The dialysis bag model will respond to hyper- or hypotonic immersion by shrinking or swelling, as an actual cell will do.