Test Techniques and Approaches

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Test techniques and approaches

Test techniques and approaches are methods and strategies used to design and execute tests in software testing. Test techniques and approaches help to reduce the number of test cases, increase the test coverage, or find different types of defects. Test techniques and approaches can be classified into black-box testing and white-box testing categories.

Test techniques and approaches examples

• Black-box testing is a type of testing that tests the functionality and features of the software ignoring its internal structure or code. Black-box testing uses techniques such as equivalence partitioning, boundary value analysis, decision table testing, state transition testing, error guessing, and cause-effect graphing.
• White-box testing is a type of testing that is based on knowledge of the internal structure and code of the software. White-box testing uses techniques such as statement coverage, branch coverage, path coverage, condition coverage, etc.
• Grey-box testing is a type of testing that needs some knowledge of the internal structure and code of the software. Grey-box testing uses techniques such as code reading, debugging tools, test design tools, etc.
• Equivalence partitioning is a technique that divides the input domain into equivalence classes that are equivalent in terms of expected output. Equivalence partitioning helps to reduce the number of test data inputs by selecting one representative value from each class.
• Boundary value analysis is a technique that tests the software at the boundaries of equivalence classes to identify any defects.
• Decision table testing is a technique that uses a table to represent the combinations of inputs and outputs of a software. Decision table testing helps to test complex logic and business rules.
• State transition testing is a technique that tests the software based on its states and valid transitions between them. State transition testing helps to test dynamic behavior of the software.
• Error guessing is a technique that uses the tester’s experience and intuition to guess the possible defects in the software. Error guessing helps to find defects that are not covered by other techniques.
• Cause-effect graphing is a technique that uses a graphical representation of inputs, outputs, and logical operators to generate test cases. Cause-effect graphing helps to test complex software systems and identify dependencies between inputs and outputs.

Tips for test techniques and approaches

• Select the appropriate test techniques and approaches based on the software requirements, technical specifications, and your test plan's test objectives and test approach.
• Use a combination of test techniques and approaches for each test level to test different quality aspects. But, try to avoid overlaps in testing.
  
• Use test design tools and techniques to generate, optimize, and automate the test case generation process.
• Analyze the test results and report them with the discovered defects.

FAQ (interview questions and answers)

1. What is the difference between black-box testing and white-box testing?
   Black-box testing is a type of testing that tests the functionality and features of the software ignoring its internal structure or code. White-box testing is a type of testing that is based on the knowledge of the internal structure and code of the software.
2. What are some advantages of grey-box testing?
   It can find both structural and functional defects. It can improve the test coverage. It can reduce the bias of black-box or white-box tests
3. Is equivalence partitioning a type of functional or non-functional testing?
   It is a type of functional testing that tests the functional requirements by dividing the input domain into equivalent classes.
4. How do you perform boundary value analysis?
   By identifying the minimum and maximum values of each input domain and selecting values just below, at and just above these boundaries for testing.

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