The “greengineers” at Newton North High School (NNHS) in the Boston suburbs had a problem. How can you use fish poop to grow fresh vegetables? Ok, so not a typical problem among high schoolers, but for the NNHS students, it was vexing.

The greengineers tackle these kinds of problems daily, including a Whole Foods request to create new uses for old bags and converting mushrooms into Styrofoam. And it’s not just theoretical answers on paper or projects in a science lab. Students at NNHS start with a question and fashion real solutions.

It’s “design thinking” in action.

As student Daniel Smith said on the school’s YouTube channel, “the beautiful part of having something like this in class is that it combines a bunch of different aspects that people would do in different classes.” To get the fish poop, full of ammonia, into another tank where bacteria live that break down the ammonia, the students needed to use mechanical engineering skills to design a pump and various systems to get the water to circulate. They also needed to identify and incorporate an appropriate energy source. And of course, they had to have a deep understanding of the ecosystem of fish, bacteria, and aquaponics (biology), because dead fish don’t poop.

“There’s a bunch of aspects that we bring together rather than isolating them,” explained Smith, “which doesn’t happen in the real world.” To ensure this kind of collaboration and hands-on learning, the greengineers have abandoned classrooms for “think tanks,” labs, and workspaces with drills, saws, sewing machines, beakers, stationary bikes, MakerBots, and more.

Bringing together different disciplines and people is an essential quality of design thinking, as is starting with a problem and using the problem-solving process to learn.

“Loosely put, design thinking,” wrote Sandy Speicher, associate partner at global design firm IDEO, a leader along with the K12 Lab Network at Stanford’s d.school in introducing design thinking to schools, “is a set of tools, methods, and processes by which we develop new answers for challenges, big and small. Through applying design thinking to challenges, we learn to define problems, understand needs and constraints, brainstorm innovative solutions, and seek and incorporate feedback about our ideas in order to continually make them better.”

Design thinking is what engineers and other problem solvers do: they identify the problem and work backward to a solution.

Design thinking is what engineers and other problem solvers do: they identify the problem and work backward to a solution. But that’s not as simple as it sounds. It requires the ability to unpack a lot of information—and not get lost in the process—cull the elements that can lead to a solution, and keep the bigger system—whether an ecosystem or a political system—in mind, as students across the nation (and globe) are learning.

Design for Change challenges students around the world to find solutions to problems in their community. Students in Laos, for example, investigated the cause of dirty bathrooms before educating the community and tackling the problem. Design for Change reaches more than 300,000 schools globally.

Closer to home, The Ellis School in Pittsburgh incorporates design thinking into several courses—from introduction to engineering design to computer

science. Recently, students addressed issues related to girls’ education worldwide.

“This type of divergent thinking is what propels the innovation our future economy and society depend on,” Kathleen Costanza wrote in a blog last year. “Employers need people with critical thinking skills more than ever.”

In the meantime, students at NNHS are taking on another form of underwater life: algae. Inspired by advances in using algae for energy, the school applied for and received grants from Save That Stuff and an MIT Sea Grant to create their own algae lab—a trailer parked behind the school. As they wrote on their website,

“Once we get the protocol down for growing algae and maintaining cultures, we will experiment with oil-high cultures. Once we are growing oil-high cultures we will then experiment with ways to extract the oil from it, and turn the oil into a bio-fuel!”

The goal, Speicher explained, is to “enable a generation of leaders” who have the tools to “build new systems and rebuild declining ones” and who can “empathically and intelligently shape the world.”

Heidi Moore contributed to this post.