[Class Report] Introduction to System Development – Week 13: Finding Bugs and Making It Better! Time for Testing & Improvement
Last week, first-year students began developing their original apps based on their own design plans. In this week’s class, they moved on to the next phase: “run it, fix it, and improve it”—a core process in programming.
■ Teacher’s Message: “Programs don’t have to be perfect on the first try”
Mr. Tanaka: “Even professional engineers don’t write perfect code on their first attempt. The essence of programming lies in repeating ‘make it, run it, fix it.’”
He encouraged students by reminding them that discovering a bug isn’t a failure—it’s a step forward.
■ Practical Session ①: Test your app with suspicion
The first exercise was to run their apps repeatedly using various types of inputs. Students intentionally entered unexpected or incorrect data to test how well their programs handled it.
Test Focus Points:
- Does it return the expected result?
- Are conditional branches working correctly?
- What happens if the input is blank?
- What if the same name is entered multiple times?
Student A: “Huh? I entered 100 points, but it says I got a B grade…?”
Mr. Tanaka: “Let’s double-check the order of your conditions.”
■ Practical Session ②: Fix the errors and refine the code
Next, students tackled each bug or odd behavior they found during testing. Some also took on refactoring, improving the readability and efficiency of their code.
Common Fixes:
- Cleaning up overlapping
ifconditions - Renaming variables to make them more understandable
- Grouping repeated code into reusable functions
Student B: “Adding comments actually made it easier for me to understand my own code.”
Student C: “At first it didn’t work well, but fixing it made me feel more attached to it (lol).”
■ Focus Time: Facing one bug with patience
In the latter half of the class, the room was filled with quiet focus as students grappled with error messages:
- Wrestling with
NameErrorandIndexError - Using
print()to debug and trace their code - Gradually achieving a sense of accomplishment as their apps came together
Student D: “Ah, I got it! The variable was in the wrong place!”
Mr. Tanaka: “That moment of realization is your biggest growth.”
■ Teacher’s Final Words
“Errors are opportunities to grow. When your code doesn’t work as expected, that’s when your skills as a programmer are tested. The experience of saying ‘I fixed it!’ is the most powerful learning of all.”
■ Next Week’s Preview: Final Touches & Preparing for User Testing
Next week marks the final phase of app completion. Students will focus on:
- Final testing
- Polishing messages and designs
- Preparing their apps to be presented and used by others
The class will also begin preparing for peer test play sessions!
By discovering and fixing problems themselves, students are now leaving visible signs of growth in their code—each line representing a new lesson learned.