4.1.1 Categories of Test Techniques and Their Characteristics

In this syllabus, test techniques are classified as black-box, white-box, or experience-based.

Black-box test techniques (also called behavioral or behavior-based techniques) are based on an analysis of the appropriate test basis (e.g., formal requirements documents, specifications, use cases, user stories, or business processes). These techniques are applicable to both functional and nonfunctional testing. Black-box test techniques concentrate on the inputs and outputs of the test object without reference to its internal structure.

White-box test techniques (also called structural or structure-based techniques) are based on an analysis of the architecture, detailed design, internal structure, or the code of the test object. Unlike black-box test techniques, white-box test techniques concentrate on the structure and processing within the test object.

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.

Common characteristics of black-box test techniques include the following:

• Test conditions, test cases, and test data are derived from a test basis that may include software requirements, specifications, use cases, and user stories

• Test cases may be used to detect gaps between the requirements and the implementation of the requirements, as well as deviations from the requirements

• Coverage is measured based on the items tested in the test basis and the technique applied to the test basis

Common characteristics of white-box test techniques include:

• Test conditions, test cases, and test data are derived from a test basis that may include code, software architecture, detailed design, or any other source of information regarding the structure of the software

• Coverage is measured based on the items tested within a selected structure (e.g., the code or interfaces) and the technique applied to the test basis

Common characteristics of experience-based test techniques include:

• Test conditions, test cases, and test data are derived from a test basis that may include knowledge and experience of testers, developers, users and other stakeholders

This knowledge and experience includes expected use of the software, its environment, likely defects, and the distribution of those defects

The international standard (ISO/IEC/IEEE 29119-4) contains descriptions of test techniques and their corresponding coverage measures (see Craig 2002 and Copeland 2004 for more on techniques).