Testing Methods

Testing Methodology:

There are three testing methodologies . They are

• Black Box Testing
• White Box Testing
• Gray Box Testing

Definition for testing Methodologies:

BLACK BOX TESTING -

              Testing without the knowledge of the internal workings of the application being tested. Tests are usually functional.Black Box Testing, also known as Behavioral Testing.

             The internal structure/design/implementation of the item being tested is not known to the tester. These tests can be functional or non-functional, though usually functional.This method is named so because the software program, in the eyes of the tester, is like a black box; inside which one cannot see.

EXAMPLE :
             A tester, without knowledge of the internal structures of a website, tests the web pages by using a browser; providing inputs (clicks, keystrokes) and verifying the outputs against the expected outcome.

WHITE BOX TESTING -

             Testing based on an analysis of internal workings and structure of a piece of software. Includes techniques such as Branch Testing and Path Testing.

White Box Testing also called as “Structural testing or Glass Box Testing”

             White box testing involves looking at the structure of the code. When you know the internal structure of a product, tests can be conducted to ensure that the internal operations performed according to the specification. And all internal components have been adequately exercised.

EXAMPLE :
            A tester, usually a developer as well, studies the implementation code of a certain field on a webpage, determines all legal (valid and invalid) AND illegal inputs and verifies the outputs against the expected outcomes, which is also determined by studying the implementation code.

GRAY BOX TESTING:-

             This is a Testing method which is a combination of Black Box Testing method and White Box Testing method.

             In Gray Box Testing, the internal structure is partially known. This involves having access to internal data structures and algorithms for purposes of designing the test cases, but testing at the user, or black-box level.Gray Box Testing is named so because the software program, in the eyes of the tester is like a gray/semi-transparent box; inside which one can partially see.

EXAMPLE:
             An example of Gray Box Testing would be when the codes for two units/modules are studied (White Box Testing method) for designing test cases and actual tests are conducted using the exposed interfaces (Black Box Testing method).