Debugging Stats, correlation vs cause and effect. Coincidence (tom and the port scan, our line drops). 280 million people in USA; every day 280 1-in-a million events happen. Stats are useful for summarizing data, extrapolating from subset, and finding correlations. Avoid superfluous confusing details. Use example of two twins killed within 2 hours on same highway in Finland on march 5th. both on bikes. Ask rather "how surprising is it?" Surprising that 2 men killed <2 hours on same day in same town? no. fact that they were twins makes no difference. Not unusual for two people to be killed in snowstorm on a busy highway on bikes. Blades of grass in a meadow. Pick any one of them and it's like 1ina billion, but it's still a certainty you will pick one. Talk about feyman's example of finding that exact plate on car in lot before talk. Find his example in the book. You cannot use post examination to evaluate probability...it already happened. "Six easy pieces". Never ever can verify an idea with data you used to get the idea. What's te chance I see that license plate! Einstein and the orbit of mercury then eclipse. We are hardwired to explain things and find patterns; leads to lots of false positives.