case design: Be aware of unwanted features

hobli

Omission detection is quite common when we design testcases, especially when using a “black box” testing, i.e, we focus on any“missing feature” as in AURS. However, this is not sufficient in some cases, weshould also verify if the tested application has implemented “extra features”which may be harmful to customers/application.

Example is shown below:

A function f(x) will change the entry of record x, so thetest criteria will be:

(1)              Is the record x changed properly?
(2)              All other records are not modified?

hobli

missing feature, refers to some features required by our customer, but our developers have not implemented.
extra feature, this is my own terminology, not necessary a formal word in software testing, what I refer to is those features which are implemented by our developers, but not required by our customers, and sometimes, those features are 'harmful'. Maybe, I should use 'extra behavior' instead
of 'extra feature'.