laziness, impatience, and hubris  
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Assessing a statistical argument on the fraudulance of the Iranian electionsby whakka (Hermit) 
on Jun 23, 2009 at 02:32 UTC ( #773831=CUFP: print w/ replies, xml )  Need Help?? 
Update: Fixed to address the actual test used, which I originally misread, from which what they calculate is numerically accurate.
A lot of attention has been garnered by the Washington Post article with a statistical argument that the elections in Iran were a fraud. I replicate part of it below with my critique of what it all means. Their argument goes like this: A random draw from the digits 09 yield a 10% probability of picking any single digit. In the election results the digit 5 occurred as the last digit 4% of the time while the digit 7 similarly occurred 17% of the time. (Apparently this also had some psychological significance.) "Fewer than four in a hundred nonfraudulent elections would produce such numbers." A testable assertion! Onto the Perl: (note that the election results had 116 observations)
Typical Output: So, from a uniform distribution between 09 of 116 random draws you would expect to find one digit occurring 4% of the time or fewer in over 20% of the cases. The odds of a digit occurring 17% of the time or higher is half as frequent yet still comfortably inside the 95% confidence interval. We fail to reject the null hypothesis of both individual tests at the 5% level, The fact remains they used arbitrary tests to arrive at this number  you would have to believe each psychological justification to say it bears any significance. It also reeks of data mining  they omit to tell us if they tested other bits of psychological trivia that happened to turn out nonsignificant. If they did then their final likelihood assessment  1 in 200  is invalid, and they should have instead pooled all of their tests, significant or not. Election fraud is a serious charge and one that should be made with stronger evidence than a few minor statistical anomalies based on flimsy adhoc reasoning. Analyses based on exit polling data, for example, are much more sound  if systematic anomalies are observed you either have to reject the polling methodology (sample bias, eg) or question the election results.
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