in reply to Re: Testing by Contract
in thread Testing by Contract

Stats ain't my forte, but wouldn't this only be true if tests A & B were both capable of detecting all the possible unknown bugs?

If this the case, then all you need to make this work is a sure fire way of designing tests that are guarenteed to be capable of detecting all possible bugs. Actually, you would probably need a way of designing two independant tests capable of detecting all possible bugs, as I doubt it would work if the two tests were the same:)

Examine what is said, not who speaks.
"Efficiency is intelligent laziness." -David Dunham
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Re: Re: Re: Testing by Contract
by chunlou (Curate) on Jul 01, 2003 at 12:52 UTC
    Since A and B are only random subsets of all possible combinations (in the case of integration testing), they are not going to detect all possible unknown bugs

    The key lies on C, the common area. If you look at the Venn diagram and if you imagine squeezing the superset T smaller and smaller, it will be less likely for C to be small--A and B must tend to overlap.

    The whole point is to estimate the total number of bugs without having to go through an exhaustive testing.

    Of course, that simple estimate probably won't be statistically very valid, since bugs are not independent. But it still gives a good conceptual insight--if a bunch of independent testers tend not to find common bugs, there're probably still pretty of bugs out there.