Domain Testing: Divide and Conquer - Testing Education

For instance, in the above example, there are two possible paths. One path is that
event A occurs and the other path corresponds to the possibility that event B occurs.
Of course, there is another possible path for all the cases when the value of
x is non-numeric. In the above example it is difficult to tell, but normally if there
were an error-handling capability incorporated in the program, the path taken in the
event of such an error would be whatever is mentioned in the corresponding error-
handling construct of the program.
In domain testing, the first main task is to partition the input domain into
partitions or equivalence classes based on some criterion. As mentioned before, the
criterion in the path analysis approach is the path. All members of one partition or
subset of the input domain are expected to result in the execution of the same path
of the program (Howden, 1976; Weyuker & Jeng, 1991; White & Cohen, 1980). In
the example above, the set of all values of variable x less than 10 forms one
partition and the set of all values of x greater than or equal to 10 forms another.
2.01.01.01.02 Mutation Testing Approach
If a program passed all the tests from a subdomain, then can one really be sure that
the program is actually correct? Either the program really is correct over that
subdomain or the tester is using a set of ineffective test cases to test the program
(DeMillo et al., 1978). This is where mutation testing comes into play.
Mutation testing involves creating a set of wrong versions of a program,
called mutants, for every subdomain over whose members the original program
seems to operate correctly. That is, it is known to have passed all the tests in that
subdomain (DeMillo et al., 1978). A mutant of a program is usually formed by
modifying a single statement of the original program (Weyuker & Jeng, 1991). The
statement that is modified will depend on which portion of the program the
associated subdomain corresponds to.
Adrion, Branstad and Cherniavsky (1982), DeMillo et al. (1978), Howden
(1981), Jeng and Weyuker (1989), Podgurski and Yang (1993), and Weyuker and
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