Domain Testing: Divide and Conquer - Testing Education

three equivalence classes. The first one contains all cases that require operating the
program over RAM capacities below 64K. The second class consists of all cases
that require operating the program over RAM capacities between 64K and 256K.
Finally, the third equivalence class consists of all cases that require operating the
program over RAM capacities greater than 256K.
Functional testing has been described in the literature as a specific form of
specification-based or black-box domain testing, which is described next .
2.01.01.02.01 Functional Testing Approach
In the context of this thesis, a function is defined as: “In programming, a named
section of a program that performs a specific task” (Webopedia, 2003, 1).
IEEE Std. 610.12 defined a function as:
(1) A defined objective or characteristic action of a system or component.
For example, a system may have inventory control as its primary function.
(2) A software module that performs a specific action, is invoked by the
appearance of its name in an expression, may receive input values, and
returns a single value. (p. 35)
Hamlet et al. (2001), Howden (1981), Howden (1986), Howden (1989),
Podgurski and Yang (1993), Vagoun (1996) and Zeil et al. (1992b) are among the
researchers that have described the functional testing approach to doing domain
testing.
Howden's work on functional testing is often cited in the literature as having
laid the foundation of black-box testing because the approach he described focuses
only on the inputs and outputs of a program’s functions and not on how the
program executes the functions. According to Podgurski and Yang (1993),
“Perhaps the most widely used form of partition testing is functional testing. This
approach requires selecting test data to exercise each aspect of functionality
identified in a program’s requirement specification. The inputs that invoke a
particular feature comprise a subdomain” (p. 170).
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