Test case design: assumption

before we design some test cases, we have to have some "assumptions" (well, u maybe
not aware of them), which are always considered to be 'true', and no need to be verified. So, we talk about test results, we should say "our application has/has not
passed/failed XX test case with XX assumption.

In case our assumption are invalid, the test result will nolonger bear any meaning,
they have to be discarded.

In real life, the assumption is hardly to be considered to be 'true' or 'false', we
can only say to certain degree, our assumptions are valid, or the probality of
assumption to be valid. I personally name this as "degree of belief".

Hence, we need take the assumption into consideration when we calculate ar  test coverage: real test coverage = designed test coverage * degree of belief.

Another think I would like to poin out is that, we should put the 'assumption' information into our test specification, so other testers and/or auditors can have a
better idea of our test case validity/coverage.