Black box testing methods

Methods of Validations:

  1. White Box Testing:

Based on knowledge of the internal logic of an application’s code. Tests are based on coverage of code statements, branches, paths, conditions.

  1. Black Box Testing:

Not based on any knowledge of internal design or code. Tests are based on requirements and functionality.

Black Box Testing:

Methods of Black box Testing:

Graph Based Testing Methods:

Every application is build up of some objects. All such objects are identified and graph is prepared. From this object graph each object relationship is identified and test cases designed accordingly to find out the errors.

Error Guessing:

This is purely based on previous experience of tester. Error Guessing is the method of guessing where errors can be hidden. For this technique there are no specific tools, design the test cases that cover all the application scenarios.

Boundary Value Analysis:

Many systems have weakness to fail on boundary. Boundary Value Analysis (BVA) is Functional Testing technique where the extreme boundary values are chosen. Boundary values include maximum, minimum, just inside/outside boundaries, typical values, and error values. this is important black box testing method.

Extends equivalence partitioning:

Test both sides of each boundary

To check the output boundaries for test cases too

Test lower, lower -1, upper, upper+1, typical values

Equivalence Partitioning:

Equivalence partition is a black box testing method that divides the input domain of a program into classes of data from which test cases can be derived. This very important black box testing method.


  • Unit testing

    To test the particular functions or code modules. Normally done by the programmer and not by testers, it requires the detailed knowledge of the internal program design and code. may be require developing test driver modules or test harnesses.

  • Incremental Integration testing

    Requires that various aspects of an application’s functionality be independent enough to work separately before all parts of the program are completed, also that test drivers be developed as needed; done by programmers or by testers.

  • Integration Testing¬†

    testing of combined parts of an application to determine if they function together correctly. The ‘parts’ can be code modules, individual applications, client and server applications and distributed systems.

  • Functional testing

    Black box type testing organize to functional requirements of an application; this type of testing done by testers.

  • System Testing

    Black box testing type that is based on overall business requirement specifications and covers the all combined parts of a system.


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