James Surowiecki on odd-looking results in the recent Venezuela referendum: “with twelve thousand voting "tables," many with multiple machines, it was inevitable that some would end up with matching scores. (It's similar to the fact that if there are 23 people in a room, the chances are 50-50 that two of them have the same birthday.) Not surprisingly, then, when international observers audited a sample of the results, they found that while there were 402 tables with matching anti-Chavez votes, there were 311 tables with matching pro-Chavez votes, too. What seemed to be proof of fraud was most likely just a statistical artifact.”
Edward Felton, on the same topic: “What evidence is there for fraud? The opposition says that the election results were inconsistent with exit polling, which they say went 58-42 in the other direction. That's a big enough swing to raise eyebrows, but it's hard to evaluate the accuracy of the exit polls based on the information available to me.”
