Domain Testing: Divide and Conquer - Testing Education

tester with a couple years experience. But it is an example of the kinds of thinking I do
expect from a working tester.
I have not specifically produced the equivalence class tables called for in the exercise.
However, my analysis of the variables provides most of the information required for
those tables.
Observations of the students’ answers:
� I don't see anything in the students’ answers (except for student4) that goes to the
question of dimension.
� I don’t see any output variables in the student answers.
� I don’t see any interactions among variables noted. Though this wasn’t specifically
called for in the instructions, I believe this is an important aspect of the skill of the
working tester. Many aspects of products are not laid out for testers directly, but
must be inferred mental models of the product that form in the normal course of
learning a product.
� I don’t see any issues or questions noted, or commentary on the sources and
limitations of their analyses.
� In almost every case, the risks provided by the students added no information over
and above the description of the corresponding equivalence class. Notice that in my
analysis, I identified one list of “domain-defining risks” for each variable, and no
separate list of equivalence classes. This is because in most cases, I felt a separate
list would add nothing to the analysis.
� The click help function was not mentioned in any of their analyses. Click help is
functionally identical to an enumerated menu of options. Just because the interface
is different does not seem to me a reason to exclude it from our testing.
� The “custom” setting applies the dimensions of the printable area of the current
printer, but this relationship is not noted in any of the student analyses. This may
indicate that the students did not review the online help, nor perform enough of an
exploration of this function.
� Because the students apparently used only empirical observation to perform their
analyses, their analyses are basically tautological. They each determined that the
input length limit for the numeric fields is 31, apparently because that is how the
software behaves. But a length of 31 is inconsistent with the obvious limits of those
functions—clearly PowerPoint is not designed to handle slides that are a billion
trillion trillion inches wide or tall. So, it seems more reasonable to question the 31
character limit than to enshrine it permanently in the test cases.
� The consistency among the answer sheets for each student suggests that the students
either collaborated with each other to produce their answers, or that they were
instructed in a very specific formula of domain testing. I don’t believe domain
testing is usefully reduced to a formula. I believe successful working testers show
more variation in their work, because of natural variations in the experiences,
temperament, exploration, knowledge, and contexts of thinking people. The lack of