Hewitt News

Bang, Crash, Boom: Scientific Discovery and Engineering Design in Seventh GradeĀ 
Ed Goodall, Science Teacher

In seventh grade science, students immerse themselves in two valuable systems of inquiry with real-world applications: the scientific method and the engineering design process (EDP). Though these two processes may appear similar on the surface, seventh graders quickly learn not only how to distinguish between them, but also to appreciate their relationship to one another — especially how the study of science can improve the engineering design process. Through a series of self-directed and hands-on labs, students learn about the scientific method and EDP not as neat or abstract concepts, but as iterative processes they can use to help answer questions and design solutions. Because seventh grade scientists lead their own learning — they ask questions, make decisions, and get both literally and figuratively messy — they approach each class meeting and each new challenge with motivation, curiosity, and commitment.

Our course began this fall with a review of the scientific method, which involves making hypotheses, gathering evidence through experimentation, and analyzing that evidence in order to answer a specific question. Next, I introduced students to the engineering design process and its focus on designing, building, evaluating, and improving solutions to specific problems. During class discussions about the EDP, students considered how brainstorming and assessing several potential solutions before committing to building specific prototypes allows engineers to work effectively. Through these conversations, students came to recognize how forethought and planning would help them work efficiently both in terms of their time and their physical resources, and they were soon ready to dig into their first engineering assignment. Their design brief tasked them with building a container that could safely transport an egg across a zipline. Working in small groups, the seventh graders began to brainstorm ideas, address potential challenges, and sketch possible designs. 

As they designed vessels that could slide smoothly across a wire and protect cargo, students started to observe patterns that would inform and improve their designs. First they noticed that the steeper the zipline, the faster their containers traveled along the wire. Soon after, they realized that rougher string or a narrow connection point between the container and the zipline increased friction, thereby increasing the time it took for their containers to move along the wire. To make sense of these observations, the seventh graders conducted a series of experiments studying slope – the steepness or gradient of a line. They tried rolling a marble down the angle of their partially opened laptop, noting that the marble traveled faster down a steeper slope. This finding led them to question whether increased weight might make the marble, and ultimately their egg containers, move faster. To test their theory, students conducted experiments to see whether different-sized ball bearings landed at the same time when dropped from the same height, and confusingly, they did. 

The students recognized that these results did not seem to fit with their previous thoughts and, with the help of Aristotle’s and Galileo’s conflicting theories on motion, knew that the answer to their experiments would not be quite as straightforward as “heavy things drop first” or “all things fall at the same rate.” To further their investigation, they tried dropping golf balls alongside ball bearings and flat sheets of paper alongside sheets that had been crumpled into balls, recording each trial with their phone or laptop cameras. Through these experiments, they realized that air resistance and an object’s shape — not weight — helped explain why an aerodynamic ball such as a golf ball would fall faster than a ball bearing. At each phase of these experiments the students developed a theoretical and practical understanding of friction, weight, and, to an extent, air-resistance, and their engineering designs improved. Through their hands-on experiments, they were able to build smarter, more effective, and more efficient egg carriers. 

Because they were learning from their own experimentation rather than from information that was given to them, seventh graders equipped themselves with a stronger understanding of gravity and a clear sense of how to apply their scientific knowledge to their work as engineers. These skills will be put to use as they look ahead to their next design project: a miniature Mars Rover (a very basic vehicle that can safely transport an egg) and a low density supersonic decelerator (LDSD) that allows the Rover to slow itself down for a safe landing on Mars. Per their design brief, they will have to build a device that can safely land itself (and its cargo), and to simulate the impact of the real Mars Rover’s landing, their designs will have to withstand a drop from several stories. To build an LDSD that can achieve these goals, seventh graders will conduct experiments with air-resistance and thrust, developing a practical understanding of thrust and Newton’s third law — that every action or force in nature has an equal and opposite reaction — to help them design parachutes and balloon thrusters that can control their Rover’s descent. 

While our class’s experiments and design challenges always encourage students to see science as iterative and flexible, the unique circumstances of teaching and learning in a pandemic this year have also helped us all recognize our learning as dynamic and adaptable. With some students learning online while others attend classes in person, my students and I have come to see how the hands-on experiments and collaborative problem solving that form the foundation of our course do not require us all to be together at the same time and place. For example, at the start of this school year I sent home some versatile equipment for physics experiments and balloons for building rocket thrusters, so that  students did not need to be in the classroom in order to participate in our experiments and activities. In addition to providing students with these physical supplies, technology has been key in enabling our class to work together and communicate with each other from home and school. To help our online learners feel connected to the classroom, we use the Meeting OWL Pro – a 360-degree camera, microphone, and speaker – when we come together at the start and end of each class meeting to review our agenda and share announcements. Meanwhile, Zoom breakout rooms allow students who are learning online to collaborate in small groups just like their peers do in the classroom. These digital tools also help me move between groups of students to answer questions, make observations, and engage in conversations about the work we are all doing together. 

It is clear that, regardless of location, the hands-on and student-directed work of seventh grade science — the time spent solving, testing, building, and creating —  helps students develop a strong grasp of the engineering design process and, more specifically, how scientific inquiry and experimentation can inform and improve engineering. Beyond these perhaps more obvious benefits are a host of skills that students cannot easily hone and that teachers cannot easily see in a traditional, lecture-based classroom. By working with their hands and with each other, my seventh graders improve their ability to work as members of a team, to take on and share leadership roles, to see how art and science are inextricably linked, and to engage with an audience as they communicate their ideas. These important habits of mind will serve them well throughout the rest of their time at Hewitt, in college, and eventually in the workplace. Building things out of simple and repurposed materials allows students to identify and design solutions for specific challenges, which ultimately leads to an energetic and enthusiastic, and hopefully lifelong, love of learning. 

A student sits at a desk with a laptop and rulers holding a timer

A student conducts an experiment studying slope by rolling items down the angle of her partially opened laptop

A student sits on the floor testing how her container moves along a zipline.

For their first engineering project, students designed and builtĀ containers that could safely transport an egg across a zipline