Technologies · Year 7

Active learning ideas

Logic Errors and Test Cases

Active learning works for logic errors because students need to see their own programs run incorrectly before they truly grasp the difference between syntax and reasoning mistakes. By testing and discussing each other’s code, students shift from passive observation to active problem-solving, building the metacognitive habit of verifying output against expectation.

• ACARA Content Descriptions
• AC9TDI8P04

• 25–50 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Collaborative Problem-Solving
• 30 min · Pairs

Pair Debug: Test Case Swap

Pairs write a simple program like a grade calculator. Partner A creates 5-7 test cases with inputs and expected outputs. Partner B runs them, logs failures, and proposes fixes. Switch roles and compare results.

Design a set of test cases to thoroughly evaluate a program's logic.

Facilitation Tip

In Pair Debug: Test Case Swap, circulate and ask students to explain why they chose each test case before they run the code, focusing their attention on logic paths rather than syntax.

What to look for

Provide students with a short, flawed program (e.g., a simple calculator with a logic error). Ask them to write down two specific test cases: one that reveals the logic error and one that shows the program working correctly. They should state the input and the expected output for each.

• Apply
• Analyze
• Evaluate
• Create
• Relationship Skills
• Decision-Making
• Self-Management

Activity 02

• Collaborative Problem-Solving
• 45 min · Small Groups

Small Group: Edge Case Hunt

Groups get a looping program with a known logic error. They brainstorm edge cases (e.g., empty lists, negatives), design test cases, execute as a team, and vote on the best fix after tracing code step-by-step.

Differentiate between syntax errors and logic errors.

Facilitation Tip

During Edge Case Hunt, provide a checklist of common edge cases (zero, negative numbers, large values) to guide groups toward comprehensive coverage.

What to look for

In pairs, students exchange a program they have written. Each student then designs three test cases (one normal input, one edge case, one invalid input) for their partner's program. They swap their test cases and run them. Students then provide feedback to their partner on whether the test cases were effective in finding issues and if the program's output matched the expected output.

• Apply
• Analyze
• Evaluate
• Create
• Relationship Skills
• Decision-Making
• Self-Management

Activity 03

• Collaborative Problem-Solving
• 50 min · Whole Class

Whole Class: Bug Auction

Students submit buggy code snippets anonymously. Class generates shared test cases on the board. Run tests live via projector, discuss failures, and auction fixes with justifications. Tally most effective tests.

Justify the iterative process of testing and refining code.

Facilitation Tip

In Bug Auction, model how to phrase bids as questions like, ‘What happens if we input 0 here?’ to keep the focus on reasoning, not blame.

What to look for

Pose the question: 'Imagine a program that calculates the area of a rectangle. What is the difference between a syntax error and a logic error in this context? Give an example of each and explain why one stops the program and the other does not.' Facilitate a class discussion to clarify these concepts.

• Apply
• Analyze
• Evaluate
• Create
• Relationship Skills
• Decision-Making
• Self-Management

Activity 04

• Collaborative Problem-Solving
• 25 min · Individual

Individual: Personal Test Suite

Each student builds a test suite for their own program. Run it repeatedly after changes, log iterations in a debug journal. Share one key insight with the class.

Design a set of test cases to thoroughly evaluate a program's logic.

Facilitation Tip

For Personal Test Suite, require students to include both a working case and a failing case in their documentation to reinforce the idea that logic must be tested, not just assumed.

What to look for

Provide students with a short, flawed program (e.g., a simple calculator with a logic error). Ask them to write down two specific test cases: one that reveals the logic error and one that shows the program working correctly. They should state the input and the expected output for each.

• Apply
• Analyze
• Evaluate
• Create
• Relationship Skills
• Decision-Making
• Self-Management

A few notes on teaching this unit

Teach this topic by making logic errors visible through immediate testing, not explanation. Start with a live coding demo where you intentionally introduce a logic error, run the program, and ask students what went wrong. Avoid lecturing about logic errors beforehand; let the confusion surface naturally. Research shows students learn debugging best when they experience the frustration of wrong outputs and then discover how test cases help them diagnose the issue. Emphasize that test cases are hypotheses about how the program should behave, which can be proven wrong, guiding correction.

Successful learning looks like students confidently identifying logic errors in peers’ programs, justifying their test cases with clear inputs and expected outputs, and revising code based on evidence from systematic testing. They should articulate why a program ‘works’ yet produces wrong answers, showing understanding beyond surface-level fixes.

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Watch Out for These Misconceptions

• During Pair Debug: Test Case Swap, watch for students assuming any test that runs means the program is correct.

  Redirect them to compare the actual output with their partner’s expected output and ask, ‘How do you know this result is right?’ Use the test case swap to highlight that running is not the same as working.

• During Edge Case Hunt, watch for students selecting only typical inputs and skipping unusual or extreme cases.

  Prompt groups with, ‘What values might break this logic even if the program runs?’ and require them to justify why each case matters, using examples from their hunt list.

• During Bug Auction, watch for students equating a program’s ability to run with having no logic issues.

  Use the auction to focus bids on outputs by asking, ‘Does the result match what we expected? If not, what should the test case look like?’ This keeps attention on logic correctness, not execution.

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Methods used in this brief

• Collaborative Problem-Solving