Next Gen Navigator
By Greg Bartus
Posted on 2019-08-22
Engineering design projects are a wonderful opportunity for students to develop science disciplinary core ideas (DCIs). (As many of you know, with the release of the NGSS, learning in engineering must be integrated with developing DCIs in physical, life, and/or Earth and space sciences.) To take advantage of this opportunity, it is important to ask questions that encourage (or necessitate) students to use specific science ideas to explain choices they make.
Let’s say I ask my students to take part in an engineering design challenge in which the goal is to design a device that will prevent a cold beverage from warming up (DCI PS3.B: Conservation of Energy and Energy Transfer—Energy is spontaneously transferred out of hotter regions or objects and into colder ones.) I give students a can of cold soda, an infrared temperature gun, and a few materials they can use to cover the can. The device has to keep the soda’s temperature from increasing more than 5°F in 20 minutes. Student designs are constrained by time, budget, and/or materials.
Students test materials, analyze their data, and design their solutions. As the instructor, I want to know how my students are applying scientific ideas or principles to design their solutions (an element of SEP Constructing Explanations). I find out by asking questions to surface students’ mental models of 1) energy moving from hotter objects to colder ones (PS3.B) and 2) the relationships among temperature, heat, and thermal energy (an element of PS3.A). These questions push my students to think more deeply about how their understanding of these “big” science ideas fits with what their observations from testing the materials are telling them. Research suggests that this questioning is the best way to help students’ thinking advance from a preconception toward the correct scientific idea.1
These are examples of the questions I ask to start conversations with my students:
These “kick-off” questions offer an opportunity for my students to share their design thinking. Students typically say their ideas come from prior experiences like using the foam holders that keep cans and bottles cool. I’ve seen my students use this type of mimicry as the basis for creative and innovative designs, but I have to be sure to dig a little deeper to get at the science ideas they are using to justify them.
My follow-up questions are drawn from elements of the DCIs PS3.A and PS3.B and the crosscutting concept (CCC) Energy and Matter—The transfer of energy can be tracked as energy flows through a designed or natural system and Structure and Function—Structures can be designed to serve particular functions by taking into account properties of different materials, and how materials can be shaped and used. For example, I ask the students whose inspiration comes from using foam can holders questions like these:
I listen carefully to answers students provide to see if they reveal any common preconceptions that did not surface before. Being mindful of PS3.A: Definitions of Energy—The term “heat” as used in everyday language refers both to thermal energy (the motion of atoms or molecules within a substance) and the transfer of that thermal energy from one object to another. In science, heat is used only for this second meaning, it refers to the energy transferred due to the temperature difference between two objects, when students say their design is “trapping cold” or “preventing the temperature from moving” or “containing heat,” I ask questions like these:
Each of these questions can lead to great student discussion and allows me to formatively assess student understanding and move students from partial understanding toward scientific accuracy. For example, if students say that “cold” and “warm” are substances, I might do a demonstration such as hitting a nail with a hammer, then ask my students why the nail head becomes warm after it’s hammered. [Note: Repeatedly throwing a ball at the same spot on a wall will yield a similar result.] Students typically arrive at the conclusion that the hammer added vibrations (motion) to the nail and that vibration is what we recognize as “warm.”
We then discuss how the temperature of the nail cools, and students say the vibrations (motion) passed from the nail to the surroundings. We’ve moved from the idea of warm and cold being substances toward the concepts of thermal energy and heat. (This is just a brief example; admittedly, the issue doesn’t usually get resolved that fast.) Then I ask students how they can use these same ideas to explain how their device keeps the soda can from warming up.
I hope these questions are helpful and inspire you to engage students in the science ideas they are learning when they take part in engineering activities. Feel free to share your experiences and any questions you use to connect science and engineering.
1National Research Council. 1997. Chapter 4: Misconceptions as barriers to understanding science. In Science teaching reconsidered: A handbook. Washington, DC: National Academies Press.
Greg Bartus will teach Earth science at Broome Street Academy in New York City this fall. He previously taught high school science courses in upstate New York for five years. In between teaching gigs, he spent 15 years leading professional development workshops on all things STEM, and providing classroom coaching for middle school teachers. Bartus has a master of arts in teaching in science education and a bachelor of science degree in Agricultural and Biological Engineering from Cornell University.
Note: This article is featured in the August 2019 issue of Next Gen Navigator, a monthly e-newsletter from NSTA delivering information, insights, resources, and professional learning opportunities for science educators by science educators on the Next Generation Science Standards and three-dimensional instruction. Click here to sign up to receive the Navigator every month.
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