I'm sure I've heard this phrase said before, but I can't seem to remember it or find it by searching.
A positive test is one where you make sure something specific happens - I hit a button and make sure it makes a noise, which is what I expect.
A negative test is one where you make sure something specific doesn't happen - I hit a button again and make sure that it doesn't explode, which it used to before the most recent round of changes.
But there's a term for a kind of test to make sure that absolutely nothing happens at all - perhaps that the button is completely disconnected, or that after changing a setting in software no changes are allowed to be made in a certain area. What's the name of that kind of test?