|There's more than one way to do things|
Re: Re: Re: Re: Re: Software Design Resourcesby BrowserUk (Pope)
|on Aug 22, 2003 at 10:38 UTC||Need Help??|
Sorry for the second post, but I thought about this some more and I wanted to get your reaction to those thoughts. If I just modified the last post you may not have seen the update.
The estimate is 200 total (possible) bugs (notice the large margin of error). (and the rest of that paragraph)
I am under the strong, and I believe well-founded, impression that in order for your probability calculation to make sense, the sample(s) used to estimate the total population are required to be random samples. This would not be the case if the testcases the programmers produce are done on the basis of experience (or best judgement).
If programmers A & B both write 20 identical test cases, which is unlikely, but not statistically impossible, then counting them as unique invalidates the statistics.
If the testcases they produce only cover 1% of the possible test cases and detect 2 bugs, there is no way to project the total number of bugs from that unless they represent a statistically valid sample from the total set of possible testcases. The only way for them to be a statistically valid sample is if they are a random selection from the total set of possibles. If they were written on the basis of best judgement they are not random.
Thats why the RTG was necessary for the approach I described.
Examine what is said, not who speaks."Efficiency is intelligent laziness." -David Dunham
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