Domain Testing: Divide and Conquer - Testing Education

combinations of valid equivalence classes of variables involved will be
considered.
• Strong Normal Equivalence Class Testing: This is called normal for the
reasons stated above and it is called strong because there will be at least one
test case for each combination of valid equivalence classes of input
variables involved.
• Weak Robust Equivalence Class Testing: This is called robust because there
is at least one variable in an input combination whose value is a
representative of an invalid equivalence class of that variable. This method
is weak because in a given combination of input variables, only one variable
has its value coming from an invalid equivalence class.
• Strong Robust Equivalence Class Testing: As mentioned before, the robust
part comes from consideration of invalid values. The strong part refers to
the fact that a single test case has multiple variables with values coming
from their invalid equivalence classes.
2.03.06 When to Use What Combination Technique?
According to Kaner and Bach (2004), when independent variables are involved, all
pairs is perhaps the most effective combination technique to use because it
generates a minimal number of combinations when compared with other
combination techniques, such as orthogonal and pairwise. It also considers several
pairs of multiple variables simultaneously. When dependent variables are present in
a program, then the cause-effect graphing technique can be used, although this is
quite a complex combination technique (part 19).
Kaner and Bach (2004) also presented a method of combining dependent
variables by constructing relationship tables for variables in a program and
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