e. Extras

Examiner Insights (What VCAA is really marking)

Examiners consistently reward responses that:

• Use precise terminology (e.g. expected output, actual output)
• Clearly distinguish between:
  • testing (identifying errors)
  • debugging (locating and correcting errors)
• Link techniques to purpose, not just description

Weaker responses tend to:

• Describe techniques without explaining why they are used
• Confuse debugging with validation
• Refer to testing tables as a way to "fix" errors

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Common mistakes (and how to avoid them)

❌ Confusing testing with validation

Validation checks that input data is reasonable

Testing checks that a module produces correct output

✔ Exam-safe phrasing:

"Testing compares expected and actual output to identify errors in program logic."

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❌ Describing debugging too vaguely

Weak:

"Breakpoints stop the program."

Strong:

"Breakpoints pause execution at a specific line of code, allowing the developer to inspect variable values and trace program logic."

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❌ Forgetting the purpose of testing tables

Testing tables:

• Do not correct errors
• Do not replace debugging
• Do provide evidence that a module has been tested

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High-value exam sentence starters (40+ ready)

Use these to structure responses efficiently:

• "Testing identified an error when the actual output did not match the expected output."
• "A breakpoint would be used to pause execution and inspect the values of variables at runtime."
• "Debugging statements allow the developer to confirm which sections of code are being executed."
• "The testing table provides evidence of testing and highlights discrepancies requiring debugging."

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Command word decoding (very examinable)

Command word	What the examiner wants
State	A short, precise fact
Describe	Characteristics or features
Explain	How and why
Justify	A decision + reasoning

Important

If a question says explain, listing is never enough.

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How this appears in Section B and C

Section B

Short explanation of:

• breakpoints
• debugging statements
• testing tables

Often 2–3 marks → definition + purpose required

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Section C

Applied context:

• incorrect output
• partial testing table
• student must identify next step

Full marks require:

• expected vs actual output comparison
• explicit reference to debugging

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Final 40+ takeaway

Remember

Testing finds errors.

Debugging fixes errors.

Testing tables prove errors exist.

Debugging techniques show where they occur.

If students can articulate that clearly, they are operating in 40+ territory.

    float price = 0f;
    float discountRate = 0f;

    // Validate price
    while (true)
    {
        Console.Write("Enter price ($1 - $500): ");
        string priceInput = Console.ReadLine();

        if (float.TryParse(priceInput, out price) &&
            price >= 1f && price <= 500f)
        {
            break; // valid input
        }

        Console.WriteLine("Invalid price. Please enter a number between 1 and 500.");
    }

    // Validate discount rate
    while (true)
    {
        Console.Write("Enter discount rate (0 - 0.5): ");
        string discountInput = Console.ReadLine();

        if (float.TryParse(discountInput, out discountRate) &&
            discountRate >= 0f && discountRate <= 0.5f)
        {
            break; // valid input
        }

        Console.WriteLine("Invalid discount rate. Please enter a number between 0 and 0.5.");
    }

    float finalPrice = price - (price * discountRate);

    Console.WriteLine($"Final price: ${finalPrice}");