# Proving that votes are being counted

I am thinking through some issues related to using machines to help count votes in an election. Imagine an electronic voting machine that accumuates vote totals electronically, and prints a paper receipt of each vote cast. Short of hand-counting all the paper receipts and comparing the totals to those generated by the machine, is there a way to prove (or at least be reasonably certain) that the machine is counting accurately?

### Re: Proving that votes are being counted

There could be some sort of checksum mechanism, and other algorithms such as are applied to banking. There was a 20/20 episode in which John Stossel mentioned the computers in the banking system. Those computers have a greater computational burden: not just additions but also subtractions, multiplications and divisions to deal with, each and every day, while voting machines just have to deal with additions on Election Day.

The issue of voting machines gets into many topics beyond the mathematical. For example, some of the discrepancies between exit polling and actual vote totals can have as much to do with psychological factors as with statistical concepts like sampling error.