Engineering Practice: Construct and Use Models and Prototypes

Engineers use a variety of types of models such as sketches, physical renderings, computer representations, and equations to depict, examine, test, and evaluate one or more parts of the design. Data from models can inform the development of prototypes—fully functional versions of the intended product that can be tested further.

“We Can’t Bring a River”

As students prepare to engineer a TarPul (a type of bridge), their teacher explains how they will use a model instead. Students share ideas for how they can model weight in the TarPul to test their designs. Watch & Reflect:

Related Practices: Consider Problems in Context, Use Systems Thinking, Communicate Effectively
Featured Unit: Evaluating a Landscape

Reflection Questions

She connects with the goal of transporting people in the TarPul by asking if students can fit inside their model. She asks students to share ideas of what they could use in place of people and what features those items would need to have.

1. It’s too expensive to make a full-scale TarPul. 2. Engineers use models to help them see how their idea might work and find any problems before constructing the final product. 3. It is faster to build, test, and improve a model than a full-size TarPul. 4. It’s safer to test this version before trying it with real people.

“Using Flower Models”

A teacher shows students the various models they will use as they design a hand pollinator. Watch & Reflect:

Related Practices: Consider Problems in Context, Assess Implications of Solutions, Apply Science Knowledge to Problem-Solving
Featured Unit: Engineering Pumpkin Pollinators 

Reflection Questions

The class wants to use models in this design challenge so they do not harm real flowers. Models are useful when something is too large (like the solar system) or small (like a cell) to bring into a classroom. We also use models when it may not be safe to interact with the real thing. For example, students may have allergies to pollen.

The teacher uses two different models. She has both physical models (test tubes, petri dishes) and paper-based models (drawings of the flowers). Each helps students to better understand the design challenge. Students might also create models for explanation, such as a sketch explaining how their hand pollinator will work in the different types of flowers.