their body, and a note plays on the computer. Cosier explains to them that the circuit closes because a current of electricity is running through their bodies.
The challenge for Cosier is that "working with an abstract idea doesn't have a singular solution." She doesn't make models when she asks them to create something, because she doesn't want to give them a solution.
"It's hard to help the students without telling them what to do," she said. "It's a struggle to keep it open-ended."
Kimberly Sheridan, an associate professor of educational psychology at George Mason University in Virginia, said physical computing is appealing in that it can help students bridge the gap between the digital and physical world.
But it's no sure thing that physical computing will actually improve students' understanding of computational thinking and computer science, said Sheridan, who has researched the impact of maker spaces on student learning.
For instance, when students are told to 3-D print something that someone else has already made, the potential for learning is minimal, she said. But if they're taught to design an object in 2-D with the goal of having it function properly in 3-D, that can lift their academic understanding.
The risk in using some tools is that they've "been made so user-friendly that it's hard to get kids to the next level of computational thinking," Sheridan said. "It's good for engaging kids initially, but we need to be able to move them to advanced content, where they are really thinking computationally and problem-solving."
While today's students are often referred to as "digital natives," Pimprikar argues that much of their interaction with technology is superficial--focused on using it to play games or check social media.
Physical computing asks them to become designers, not just users of technology, she says. It forces them to develop prototypes of products and go through multiple testing to get to the final product. And it reinforces computing practices through open-ended exploration where "creativity can grow and flourish," Pimprikar contends.
Physical computing, which is about the interaction between the person and the machine, also has the potential to make students think differently about technology and make better choices about using it, argues Tom Igoe, a professor from New York University and co-founder of a software and hardware company, Arduino.
"Our lives are affected by digital technology, but we don't always see how we are impacted by it," Igoe said. "When you have a better understanding of the technology, you make better choices on how to use it."
Closing the Skills Gap
But even supporters of physical computing see obstacles to its growth in K-12. One is that many teachers aren't trained in how to teach computer science or computational thinking, and so they're likely to need a lot of professional development to close that gap.
"If you don't feel comfortable teaching it, then it's going to take a long time," said Cosier, the teacher from Virginia. "It's not for the novice...You have to self-educate, and really see the benefits of bringing it into the classroom."
Making a commitment to teaching physical computing also carries a pricetag, as the Adams 12 Five Star district, outside Denver, discovered. The district implemented a new 7th grade computer science curriculum this school year, and to meet the standards, they purchased physical computing devices, like the micro-controller Micro:bits. It cost roughly $30,000 to purchase Micro:bits for the 11 middle schools in the district, Otto said.
"You have to find ways to get creative with funding," Otto said. "Our district saw the value in teaching this and shifted things around in the budget and made it happen."
The Colorado district was also helped by a partnership with Colorado-based electronics retailer Sparkfun Electronics. The company provided the district with tools it develops, Micro:bits, and offered continuous professional development for teachers.
Students in the Adams 12 Five Star schools are now using Micro:bits tools to learn about codi