If you’ve spent any time coding with students, you know the moment well. A student runs their project, the robot spins the wrong way or freezes entirely, and their face falls: “It’s broken.” For many students—and, honestly, for many of us—that moment can feel like failure, and the instinct is to fix it quickly and move on before frustration sets in.

But what if that moment isn’t a detour from learning? What if it’s one of the richest learning opportunities a coding project has to offer?

Every student who codes will eventually write a project that doesn’t behave the way they imagined. Bugs aren’t a sign that something has gone wrong with our teaching—they’re a natural and genuinely valuable part of learning to code. When we treat debugging as a skill worth teaching, and even celebrating, we help students build the resilience, creativity, and problem-solving habits that serve them well beyond the robotics classroom.

A Paradigm Shift: From Accidents to Opportunities

The first step is a shift in mindset, both for our students and for ourselves. Too often, bugs get framed as accidents—stressful interruptions to clear away as quickly as possible. But a growing body of research invites us to see them differently. Researcher Yasmin Kafai has described an approach she calls “Debugging by Design", in which students don’t simply fix bugs but intentionally create and investigate them, becoming agents of their own learning and of the process of making and solving mistakes.¹

In studying how students designed bugs in their own projects, Deborah Fields and her colleagues describe a constructionist shift in which bugs become “objects to think with and objects to share with,” rather than mistakes to hide.²

This reframe matters because debugging is part of the learning, not a pause in it. When we jump in too quickly with the answer, we may solve the immediate problem, but we also take away the chance for students to practice persistence, reasoning, and independence. Instead, we can carry that same spirit of curiosity straight through the debugging process, treating a bug as one more problem worth solving rather than a roadblock. This is very much a “go slow to go fast” situation: the time we invest in helping students work through a bug pays real dividends in the understanding and independence they build, which they carry into the next one.

There is an emotional dimension to this, too. In Fields and her colleagues’ research, students who designed and wrestled with their own bugs moved away from frustration and toward comfort, confidence, and even a sense of control—shifts they still described weeks afterward. That movement from “I can’t” to “let me figure out why” is the very foundation of a resilient problem solver, and it is closely tied to the productive struggle we want students to experience throughout any open-ended challenge. It also helps make our classrooms what they should be: safe places where mistakes are expected, examined, and even celebrated as part of how real learning happens.

What You Need to Know to Debug

Of course, mindset alone doesn’t fix a robot. To debug a project, you and your students need a shared way to approach the problem. The process begins with staying calm and modeling the curiosity you want to see. From there, debugging comes down to three guiding questions:

• What is the project supposed to do? You can’t find a bug until you know what success looks like.
• How is it trying to do that? Walk through the logic of the code and the build, one piece at a time.
• Where does it go wrong? Compare what should happen with what actually happens, and narrow down the gap.

Building a Troubleshooting Toolbox

That’s where some specific, teachable tools come in. In VEXcode 123, VEXcode GO, and VEXcode VR, two built-in features make bugs visible:

• The Step Button runs a project one block at a time, so students can watch exactly what the robot does instead of guessing.
• Block highlighting shows which block is running in real time, helping students connect a line of code to a behavior they can see.

It also helps to know that bugs tend to fall into a few predictable categories—what we might call bug “buckets.” When something goes wrong, these give students a place to start looking:

• Sequence bugs, where blocks are in the wrong order (a “turn left” where a “turn right” belongs).
• Logic bugs, where the reasoning is off (an if and else swapped, or a block sitting outside a loop when it belongs inside).
• Configuration bugs, where the code is fine but the setup isn’t (motors assigned to the wrong ports).
• Hardware bugs, where the problem is physical (a loose wheel, a robot that isn’t connected, or one that starts from a different spot each time).

Sorting bugs into buckets serves as a thinking tool for students. It is a way to move from “it’s broken” to “let me check whether this is a logic problem or a hardware problem.” That’s a process, but a flexible one, and it leaves plenty of room for creativity.

Let Students Build the Bugs

This is where debugging becomes genuinely fun—and, perhaps surprisingly, where some of the deepest understanding takes root. Once students have practiced finding bugs, invite them to create some of their own. Challenge each student to design a project with two or three intentional bugs, then trade with a partner, or even try to “stump the teacher.”

This flips debugging from a chore into a creative challenge, and it is deceptively powerful: to bug a project on purpose, a student has to genuinely understand the concept behind the code they are deliberately breaking. Making a clever bug can demonstrate understanding just as clearly as writing clean code does—sometimes more so. A few things make the activity work:

• Intention is everything. Have students leave a note in their project explaining what it’s supposed to do. A partner can’t debug effectively without knowing the coder’s goal.
• There’s more than one way to fix a bug. Comparing solutions helps students discover that the same problem often has several valid fixes—a great springboard for discussion.
• Sharing lowers the stakes. When bugs become puzzles to swap and solve together, the fear drains out of them. The more students meet bugs in a low-pressure, social way, the more confident and persistent they become.

A “Bug Board” can give students a visible place to post and celebrate bugs they have solved, turning debugging into something the class shares rather than something students hide. And, if you teach with VEX 123, the Find the Bug STEM Lab helps you guide students through a debugging process in a fun, playful way.

Bring It Back to Your Classroom

It is a small shift with a large payoff. When we stop treating bugs as failures to be erased and start treating them as opportunities to be explored, debugging becomes one of the most valuable parts of learning to code. Students walk away not only with a working project, but also with creativity, resilience, and a flexible problem-solving process they can carry into any challenge—in robotics and well beyond it.