PhET Interactive Simulations: Putting Students in Control of STEM Learning


It’s hard to find a physics or chemistry teacher who doesn’t use PhET Interactive Simulations, a free online science and math simulation platform founded in 2002 by Nobel laureate Carl Wieman at the University of Colorado Boulder. These beautifully designed STEM explorations are loved by students and educators alike. The library of 160 simulations offers a variety of possibilities: students can experiment with different states of matter by changing temperatures and pressures, design and test electrical circuits, or investigate how gravity affects the movement of planets, to name a few. Translated into 106 languages, these simulations are now used 250 million times a year worldwide.

PhET simulations help children around the world study under a variety of challenging conditions, including COVID restrictions and military conflict. Ukrainian children use PhET simulations to stay engaged in learning, even as they hide in bomb shelters or adjust to life as refugees. Between April and June, PhET counted nearly 200,000 users of Ukrainian-language simulations as students worked to complete their school year — a 37% increase over the previous year.

This year PhET celebrates its 20th anniversary. I met Kathy Perkins, who has been the director of PhET since 2008 and originally joined PhET in 2003 as a postdoctoral associate with Carl Wieman.

Julia Brodski: Nowadays everyone understands why we need online education. But PhET started relatively early, in 2002. What was the initial motivation and vision?

Kathy Perkins: When Carl Weiman won the Nobel Prize, he presented his research to a very diverse audience. He tried to use interactive visualizations to bring his complex physics ideas to life, and saw both a greater engagement and a deeper understanding with his audience. This experience led to the idea of ​​transforming learning with interactive educational simulations where students can openly explore physical phenomena, manipulate the controls directly, choose from multiple representations, and try out different setups. The core design principle is interaction with direct and dynamic feedback.

JB: PhET is such an intuitive and playful environment. What leads the design?

CP: We focus on creating opportunities for student agencies, driven by curiosity and challenge. There is no set path through a PhET simulation, rather it is an inviting and open space. We are also strongly guided by educational research, creating designs to address students’ known problems. The result is a very flexible and fun learning tool.

JB: How do you see the future of traditional and online science labs?

CP: I see online labs and hands-on labs as great in combination, but for both we need to go beyond ‘tradition’. Recent research by Carl Wieman and Natasha Holmes (Introductory Physics Labs: We can do better) shows us that to develop the scientific problem-solving skills we aspire to as educators, students must be put in charge. Students must make the important decisions about the experiment and justify those decisions. Structured or “traditional” labs have shown little to no effect in developing students’ scientific problem solving.

Simulations can be effective and efficient in helping students discover important concepts and quickly experiment and test their ideas. Practical labs are great for developing skills with physical equipment, debugging problems, and tackling real-world challenges like errors and uncertainty. However, not all students have access to physical equipment. With funding from the Moore Foundation, we will add sources of uncertainty to some PhET simulations to deepen access to and understanding of data fluidity.

JB: How does PhET increase educational opportunities for resource-constrained communities?

CP: Our mission is to increase scientific and mathematical literacy worldwide by expanding the access to and impact of PhET simulations. Our simulations are freely accessible from our website and can be downloaded for offline use by communities without reliable internet. With support from the Yidan Prize Foundation and Mastercard Foundation, we recently launched a new PhET Global initiative, deepening our international work. We are currently focusing on Latin America and Africa, expanding translation, supporting communities of teachers and education researchers, and establishing cohorts of PhET fellows to serve as PhET experts and support teacher professional development on the ground.

JB: PhET is 20 years old this year. I’m curious, what has changed for the platform over the years?

CP: We started with college-level physics classes. Over the years, we expanded into chemistry, then high school math and science, and now early math. Working with secondary school students led to an important evolution. Our team of educators, researchers, and software developers needed to improve our design approaches, using implicit scaffolding to support productive exploration, while keeping the simulations open, explorative, and fun.

We also expanded how PhET simulations can support the entire education community, including researchers and education companies. We have developed a collaborative program and are bringing forth a new line of PhET simulations that are customizable and have back-end data to enable research on learning, personalized feedback, and more authentic assessments.

Finally, we took a deep dive into the work of Inclusive Design, which integrates accessibility features. And we launched a Diversity, Equity, Inclusion, and Belonging (DEIB) in STEM Education initiative, working with educators and students to create a comprehensive strategy for how PhET can support equal STEM learning experiences for all.

JB: Building on the impact PhET has already had, now what?

CP: Even with over 100 simulations, we have more math and science concepts to cover. It takes a lot of time, expertise and money to build high quality resources, but the investment really pays off when you see that one simulation is used millions of times. There is much to be done to improve STEM education worldwide. We know we are making an impact. Yet there are many teachers and students that we have not reached yet. Our goal forward is to ensure that: each student gets chance to fall in love with math and science.

Put on your student hat and try out PhET simulations – your science curiosities could always use a revamp!