There is always a good deal of controversy surrounding elections and in particular, whether an election is 'fair' or not. As I have been working on a project with the Open Source Digital Voting Foundation I've been exposed to this from time to time.
This controversy arises in many different guises. There is a group that is absolutely against using computers in any way shape or form to run elections. Given that we need to count the votes of some 200 Million people in this country alone, it seems far fetched to try to do that without a computer involved anywhere.
Others say that the act of looking at a ballot and determining the votes cast should only done by people, working in well organized teams with carefully designed procedures. They refer to this as the 'gold standard' of counting, the only way to be really sure that we are counting votes correctly.
That is not quite as far fetched. But also not self evident. Here comes a study that tries to rigorously measure the error rates of hand counted ballots. They say:
'"It is probably impossible to completely eliminate errors in hand counting of ballots," Byrne said. "However, there are new auditing methods that capitalize on advanced statistical procedures that can help ensure that final election results better match what is actually on the ballots. It is important that we become aware of the limitations of current methods and develop alternative ways to improve the accuracy of election results."' (from Rice University)
The bottom line result that they found was that "Hand counting of votes in post election audit or recount procedures can result in error rates of up to 2 percent." You can easily recall recent elections that were decided by less than 2 percent, right?
Bruce Schneier (a highly respected cryptography and security expert) says:
"All voting systems have nonzero error rates. This doesn't surprise technologists, but does surprise the general public. There's a myth out there that elections are perfectly accurate, down to the single vote. They're not. If the vote is within a few percentage points, they're likely a statistical tie. (The problem, of course, is that elections must produce a single winner.)" (see Bruce Schneier's Blog)