Activity 01
Pair Debug Relay: Sprite Path Fix
Pairs receive a block-based program with a sprite taking a wrong path due to a sequence error. One student traces the code aloud while the other suggests fixes; they swap roles after each test run. Run the program in Scratch or similar to verify.
Analyze common types of errors in block-based programming.
Facilitation TipDuring Pair Debug Relay, have students alternate roles every two minutes to keep both partners engaged and accountable for the fix.
What to look forPresent students with a short block-based program containing one obvious bug (e.g., a missing 'move forward' block in a sequence meant to draw a square). Ask them to identify the bug and explain in one sentence what needs to be changed to fix it.
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Activity 02
Bug Hunt Scavenger: Printed Code Cards
Print 10 code snippets with common errors like infinite loops or missing events. Small groups sort cards into 'works' or 'buggy' piles, then fix one each and present to class. Use magnifiers or highlighters for emphasis.
Explain systematic approaches to locating and resolving bugs.
Facilitation TipIn Bug Hunt Scavenger, circulate with a checklist to note which pairs persist in checking each line of code, reinforcing thoroughness.
What to look forProvide students with a simple program with a known bug. Ask them to write down the steps they took to find the bug and then describe what the program will do correctly after the bug is fixed.
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Activity 03
Prediction Station: Before and After
Set up stations with buggy code on devices. Students predict outcomes on worksheets, fix the bug, then re-run and compare. Rotate stations, discussing surprises in whole class debrief.
Predict the outcome of a program after a specific bug is fixed.
Facilitation TipFor Prediction Station, require students to write their predicted output before running the code, creating a visible gap between expectation and reality.
What to look forPose the question: 'Imagine your program is supposed to make a character say 'Hello' and then jump, but it only jumps. What are two different things you would check in your code to find the problem?'
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Activity 04
Class Debug Challenge: Maze Escape
Project a shared maze program with multiple bugs. Whole class votes on fixes via hand signals or polls, tests collectively, and celebrates correct predictions.
Analyze common types of errors in block-based programming.
Facilitation TipDuring Class Debug Challenge, assign specific sprites to groups so students practice debugging for others, not just their own work.
What to look forPresent students with a short block-based program containing one obvious bug (e.g., a missing 'move forward' block in a sequence meant to draw a square). Ask them to identify the bug and explain in one sentence what needs to be changed to fix it.
UnderstandAnalyzeEvaluateSelf-ManagementSocial Awareness
Generate Complete Lesson→A few notes on teaching this unit
Teach debugging by modeling your own thought process aloud: point to a block, say what you expect it to do, run the code, and react visibly when it fails. Avoid fixing errors for students; instead, ask guiding questions like, 'What should happen next?' to keep them thinking. Research shows that students learn debugging best when they experience failure as a normal part of problem-solving, so normalize errors early and celebrate persistence over perfection.
Students will confidently identify blocks causing errors, explain their fixes in clear steps, and predict program behavior before testing. By the end, they will approach debugging methodically, documenting their process and sharing solutions with peers.
Watch Out for These Misconceptions
During Pair Debug Relay, watch for students who skip testing after making a change, assuming the fix worked without verifying.
Pause the relay after each change and ask partners to explain what they expect to see happen next, then run the code together to compare expectations to results.
During Bug Hunt Scavenger, watch for students who only look for missing blocks and overlook incorrect sequences or wrong sprite assignments.
Have students cross off each line of code on their printed cards as they test it, forcing them to examine every block in order.
During Prediction Station, watch for students who rush through predictions without linking them to specific blocks.
Require students to annotate their prediction sheets with the exact line of code they think is causing the issue, then test that line first.
Methods used in this brief