You may tell them, “This whirligig is a prototype—the first model of its kind. Your job is to develop a model that will fall more slowly. It needs to be able to land, just like the spacecraft was able to land on Mars.”
Then, begin by illustrating what happens when you drop it. It will likely spin, but it will fall very quickly. The students’ job is to design something that will move toward the ground at a slower rate.
Defining, Refining, and Using a Model
When your students design and build their models, they need to compare them in order to improve upon their designs. Half of the kids may start to drop their whirligigs, while the other half may be watching.
You may ask your students, “Was that a fair test?” And they will likely say, “No way! Those guys dropped theirs sooner than these guys.” It often takes a little while for the kids to figure out that there is no way you can get a bunch of kids standing up there and dropping these things at exactly the same time; however, one person can hold two of them and drop at the same time.
Now, after they've allowed their spacecraft to fall, they need to figure out how they can determine which in the class is the slowest. The kids generally come up with that pretty quickly—doing it one pair at a time. After you have one trial, the winner of that trial competes with the next student. They compare those two.
And usually what happens is you find out which one is the winner.
Using Mathematical and Computational Thinking
You can create a template on the computer and make some whirligigs that are exactly the same size. You may have your students measure the area of the wings. And then they're able to drop these, typically from a ladder, and measure the fall time and then graph the data.
One conclusion that the students draw, of course, is that as the whirligig falls, it hits the air. The air slows it down, but it doesn't just slow—it spins while it slows. There are really good opportunities here to talk about both air resistance and forces and energy. It's important that the teacher not simply explain it to the students; the students are the ones who should come up with the explanation.
You may say to your students at this point, “Let's suppose now you're an engineer, you work for NASA, and you're going to make some recommendations about what's the best way to design a whirligig so it will land successfully in the atmosphere of Titan. How would you go about doing it?”
Of course, the students need to think about the evidence they've collected, and they use that evidence to construct a really clear argument for NASA about the best sort of design.
Obtaining, Evaluating, and Communicating Evidence
They can go on to develop an actual “design brief” about what a spacecraft should look like—not only the shape and form, but also what it’s made out of based on other information that they find. And then, they can evaluate different designs and see which are most effective.
Importance of Science and Engineering Practices in Science Education
My main point, really, is not just for you to know what the practices are—you can read a list of them. The important thing is to know why they're important in science education. They need to be combined with the core ideas, so your students never learn core ideas separately from practices, and your students never do practices separately from core ideas. All eight of the practices refer to both science and engineering, and the way you can tell the difference is: If students are trying to answer a question about the natural world, it's science; if they're trying to solve a problem, it's engineering.
My concluding thought is that it's not so important what students know as what they can do with what they know. And that's reflected in the eight science and engineering practices.
Dr. Cary Sneider hosted a webinar titled "Inquiry Is Alive and Well in the NGSS" on Tuesday, Nov. 6, 2018. View the recording to learn more about how the Science and Engineering Practices relate to inquiry.
*Next Generation Science Standards and logo are registered trademarks of Achieve. Neither Achieve nor the lead states and partners that developed the Next Generation Science Standards was involved in the production of, and does not endorse, this product.
This blog is based on a Professional Development video from HMH Science Dimensions.