Test Techniques
Some test techniques apply more to specific situations and test levels; others apply to all test levels. When creating test cases, testers generally use a combination of test techniques to achieve the best results from the test effort.
The use of test techniques in the test analysis, design, and implementation activities can range from very informal to very formal. The appropriate level of formality depends on the testing context. It includes the maturity of test and development processes, time constraints, safety or regulatory requirements, the knowledge and skills of the people involved, and the software development life cycle model being followed.
Types of Test Techniques
Black-box test techniques (also called behavioral or behavior-based techniques) are based on an analysis of the appropriate test basis. These techniques are applicable to both functional and non-functional testing. Black-box test techniques concentrate on the inputs and outputs of the test object without reference to its internal structure.
There are several black-box techniques, such as equivalence partitioning, boundary value analysis, decision table testing, state transition testing, and use case testing.
White-box test techniques (also called structural or structure-based techniques) are based on an analysis of the architecture, detailed design, internal structure, or code of the test object. Unlike black-box test techniques, white-box test techniques concentrate on the structure and processing within the test object.
White-box techniques include statement testing and coverage, decision testing and coverage, and the value of statement and decision testing.
Experience-based test techniques leverage the experience of developers, testers, and users to design, implement, and execute tests. These techniques are often combined with black-box and white-box test techniques.
Experience-based techniques can help identify tests that were not easily identified by other, more systematic techniques. Depending on the tester’s approach and experience, these techniques may achieve varying coverage and effectiveness. These techniques can make coverage challenging to assess and may not be measurable.
Experience-based techniques are error guessing, exploratory testing, and checklist-based testing.
