Lesser-Known Concepts Explored with Examples

 

1. Mutation Testing:

   • Description: Mutation testing is a technique to evaluate the quality of test cases by introducing small changes (mutations) to the codebase and checking if the existing tests can detect these mutations.
   • Example: Suppose you have a function that calculates the square of a number. A mutation could involve changing the multiplication operator (*) to addition (+) in the function. If the test suite fails to catch this mutation, it suggests a gap in the test coverage.

2. Exploratory Testing:

   • Description: Exploratory testing is an approach where testers explore the software application dynamically, learning about its behavior, and designing test cases on the fly rather than following predefined test scripts.
   • Example: A tester explores a newly developed mobile game by interacting with different levels, trying various strategies, and observing how the game responds. They might uncover issues such as inconsistent difficulty levels or unexpected game mechanics during this exploration.

3. Pair Testing:

   • Description: Pair testing involves two testers working together, sharing ideas, and collaborating to perform testing activities, which can lead to more effective defect detection and knowledge sharing.
   • Example: Two testers collaborate to perform regression testing on a web application. While one tester executes test cases and navigates through the application, the other observes and takes notes, providing immediate feedback and suggesting additional test scenarios.

4. A/B Testing for Quality Assurance:

   • Description: A/B testing in the context of quality assurance involves comparing two versions (A and B) of a product to determine which one performs better in terms of quality metrics such as user satisfaction, error rates, or performance.
   • Example: A software company releases two versions of its mobile application update with different login mechanisms. Version A uses traditional username-password authentication, while Version B introduces biometric authentication. User feedback and performance metrics are analyzed to determine which version provides a better user experience and overall quality.

5. Negative Testing:

   • Description: Negative testing involves testing the application's ability to handle invalid or unexpected inputs, actions, or conditions to ensure robustness and reliability.
   • Example: In an e-commerce website's search functionality, negative testing involves entering special characters, long strings, or non-existent product names to verify that the system handles such inputs gracefully and provides appropriate error messages.

6. Model-Based Testing:

   • Description: Model-based testing uses models to represent the behavior of the system, from which test cases are automatically generated, helping to achieve thorough test coverage and efficient testing.
   • Example: A model representing the different states and transitions of an elevator system is used to automatically generate test cases. These test cases verify the system's behavior under various scenarios such as normal operation, emergency situations, and maintenance mode.

7. Heuristic Evaluation:

   • Description: Heuristic evaluation involves experts assessing the usability of a system based on established usability principles (heuristics) to identify usability issues and potential improvements.
   • Example: An expert evaluator assesses a website's checkout process based on usability heuristics such as visibility of system status, match between system and the real world, and user control and freedom. They identify issues such as unclear error messages, confusing navigation, and lack of feedback during the checkout process.

8. Domain Testing:

   • Description: Domain testing focuses on testing specific areas or "domains" of the application that are known to be critical or high-risk, ensuring thorough testing coverage in those areas.
   • Example: In a banking application, domain testing might focus on critical functionalities such as account management, fund transfer, and transaction processing. Test cases are designed to cover various scenarios such as valid and invalid transactions, account balance updates, and error handling.

9. Non-Functional Testing:

   • Description: Non-functional testing assesses aspects of the system's performance, security, usability, and other quality attributes beyond functional correctness.
   • Example: Performance testing of a web application involves simulating a large number of concurrent user requests to measure response time, throughput, and resource utilization. The goal is to ensure the application performs well under expected loads and remains stable during peak usage periods.

10. Fuzz Testing:

    • Description: Fuzz testing involves feeding the system with invalid, unexpected, or random data to uncover vulnerabilities, security flaws, or stability issues.
    • Example: A security tester uses a fuzzing tool to send malformed input data (e.g., random strings, corrupted files) to a network protocol implementation. The tester monitors the system for crashes, unexpected behavior, or security vulnerabilities triggered by the fuzzed input, helping to identify and mitigate potential risks.