Update: I like the idea of knowing the standard deviation, ...
For this problem -- testing a sparse bitvector implementation -- moritz' simplified calculation appears to be 'good enough' for my purpose. I'm not capable of assessing how applicable it would be to the math you came up with for my multi-vector hashing (ie. weird bloom filter) project.
However, there is one way that these two projects may become connected. In that, if my sparse bitvector implementation proves to be sufficiently speedy, I may recode the multi-vector hashing algorithm to use it because: a) it would great;y reduce the memory requirement; b) it would opne up the possibility of increasing the discrimination by using more than 10 vectors. (But that's a project for another day :)
With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.