Voting Project Needs Python People

Andrew Dalke adalke at mindspring.com
Wed Jul 23 00:11:07 CEST 2003


Alan Dechert:
> catch it.  If one percent of the electronic votes were altered (evenly
> distributed), you will find one mismatch for sure after checking only a
> dozen or two ballots.

Actually, around 70 ballots.

The odds of finding one ballot to be wrong is 1%, so there's a 99%
chance that it's unaltered.  There's a 0.99*0.99 chance that two are
unaltered, and in general a 0.99**n chance that n are unaltered.

To get even odds of noticing an error requires

  0.99**n == 0.5
  --> log(0.99)*n == log(0.5)

>>> math.log(0.5) / math.log(0.99)
68.967563936528421
>>>

about 70 verifications.

                    Andrew
                    dalke at dalkescientific.com






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