Domain Testing: Divide and Conquer - Testing Education

and B) overlap and someone were to select test data from the area that forms the
intersection of the two partitions, how would one decide whether to consider the
test data as belonging to partition A or to partition B, or both?
Ntafos (1998) proposed that one way to resolve the problem of overlapping
subdomains is to further partition the overlapping portion until one gets disjoint
subdomains. Other researchers have relaxed their requirements and considered the
possibility of overlapping subdomains in their analyses, observing that in practice,
overlapping subdomains are very probable (Jeng & Weyuker, 1989; Kaner et al.,
1999; Weyuker & Jeng, 1991).
2.01.05 Size of Subdomains – Equally Sized or Unequally Sized?
Most partition testing discussions in the literature do not necessitate forming
equally sized domains because the size of the subdomains is an irrelevant criterion
for them. However, Chan et al. (1998) and Weyuker and Jeng (1991) have asserted
that forming equally sized partitions actually helps improve the effectiveness of
detecting failures by partition testing over random testing. There is a detailed
discussion about this under section 2.02.02.
2.02 Selecting Representatives from Subdomains
Partitioning the input domain is only half the battle. The next task is to select
candidates from each partition to represent their respective partitions. The literature
outlines some visible distinctions in how the selection of representatives can be
done:
• Random Selection
• Proportional Partition Testing
• Risk-Based Selection
o Boundary Value Analysis
o Special Value Testing
o Robustness Testing
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