The body overseeing elections in the Australian state of New South Wales (NSW) has acknowledged researchers’ claims of a bug in the software it uses to count votes. The NSW Electoral Commission (NSWEC) has corrected an error detected and described by researchers Andrew Conway and Vanessa Teague, and verified by computer science academics from the University of Melbourne and the Australian National University. The bug relates to extrapolation of voting patterns, a technique used in some Australian jurisdictions where a Single Transferable Vote (STV) system is used. Voters’ second preference candidate can secure a vote if the first preference has already been elected to a chamber using proportional representation.
Counting votes under STV can be laborious, so some jurisdictions decide to just grab a random sample of votes and then use software to extrapolate results based on that sample.
That’s the case in NSW local government elections (like local authorities in the UK, city or county governments in the USA). But the researchers found an error in the NSWEC’s software for counting randomly-selected votes.
The researchers aren’t saying the software got the election wrong, rather that it mis-counted votes and therefore reduced candidates’ chances to be elected based on the random samples of votes chosen in elections for the council in the town of Griffith. But it reduced the likelihood a long way: from 91 per cent to 10 per cent.