Criterion D: Functionality and Extensibility
Criterion D assesses the functionality of your product by evaluating how well it meets the Criteria for Success from Criterion A and how extensible your solution is for future improvements. This criterion is primarily supported by a video demonstration of your product, which showcases its functionality, highlights key features, and demonstrates extensibility through detailed explanations.
🎯 Key Components of Criterion D
1. Preparing the Video Demonstration
The video demonstration is a critical component for Criterion D. It provides the primary evidence of your product’s functionality and extensibility. To ensure your video meets IB expectations:
- Script Writing: Write a clear and concise script for the video to ensure all required points are covered systematically.
- Time Management: The video must be less than 7 minutes long. Plan the content carefully to fit within the time limit.
- Audio Quality: Use a clear voice for explanations, avoiding background noise. Consider using a microphone for better audio quality.
- Screen Recording Software: Use reliable tools such as:
2. Demonstrating Functionality
Showcase all features of your product, ensuring they meet the Criteria for Success outlined in Criterion A. Use subtitles or captions in your video to highlight which success criterion is being demonstrated at each stage.
Tips for Demonstrating Functionality:
- Start with an Overview: Provide a brief introduction to your product and its purpose. Mention whether you are an SL or HL student (optional but recommended).
- List Key Features: Present a list of features to be demonstrated in the video.
- Test Plan: Use the Test Plan from Criterion A to demonstrate the functionality of your product with appropriate test data. Ensure you:
- Include a variety of test cases, including edge cases and typical use cases.
- Show evidence of changes made to data structures and/or files after each test.
Example Video Outline:
- Introduction (30 seconds):
- Introduce yourself and state the purpose of the product.
- Mention SL or HL level (optional).
- Feature Demonstration (3–4 minutes):
- Show key functionalities using real-world data or sample datasets.
- Highlight Criteria for Success using subtitles.
- Demonstrate how each feature operates and how it meets user needs.
- Testing (2 minutes):
- Demonstrate test cases from the Test Plan, showing inputs, expected outputs, and actual outputs.
- Highlight evidence of data changes or updates in the program.
- Extensibility (30–60 seconds):
- Quickly demonstrate the extensibility of your program using:
- UML diagrams (e.g., from BlueJ for Java projects).
- Clear organization of classes, methods, and meaningful identifiers.
- Inline comments showing complex code areas.
3. Highlighting Extensibility
Extensibility refers to how well your product is designed for future improvements or adaptations. This can be shown through the structure of your program, code modularity, and inline comments.
How to Show Extensibility:
- UML Diagrams: Use tools like BlueJ (Java) to present a UML diagram that illustrates the relationships between classes and methods.
- Inline Comments: Point out inline comments in your code that explain complex methods or algorithms.
- Reusable Design: Demonstrate that your program is built with reusable components such as general-purpose classes or modules.
- Scalability: Highlight any features that allow the program to scale or adapt, such as:
- Adding new functionality without breaking existing features.
- Flexible data structures that can handle additional data types or larger datasets.
4. Preparing Sample Data
Prepare appropriate sample datasets to demonstrate the functionality and robustness of your solution during the video. Include:
- Typical data inputs that represent real-world usage.
- Edge cases or uncommon inputs to demonstrate error handling and robustness.
- Data that showcases the program’s ability to modify, save, or retrieve information dynamically.
5. Common Pitfalls to Avoid
- Overly Long Video: Ensure your video is less than 7 minutes. Moderators are not required to watch videos longer than this.
- Skipping Features: Demonstrate all key features and highlight how they meet the success criteria.
- Poor Audio or Visual Quality: Use good screen recording software and ensure clear audio for explanations.
- Superficial Extensibility Evidence: Clearly explain and demonstrate the structure of your program to showcase extensibility.
Links to Other Criteria
By following these steps and tips, your Criterion D submission will clearly demonstrate the functionality and extensibility of your product, ensuring a strong score in this criterion.