
Six Degrees of Swine Flu - soundsop
http://www.fivethirtyeight.com/2009/04/six-degrees-of-swine-flu.html
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dreish
Sunday, the swine flu story breaks. On the radio the next morning, it's even
bigger. I go in to work, and one person is home sick for the day -- someone
I've never known to take a sick day. The next morning he still sounds awful
over the intercom, and goes home sick again later in the day.

True story ends. Now the hypothetical:

Tuesday evening, I get a robo-call asking me to press 1 if I know someone with
swine flu, and 2 if I don't. I pause for a minute; do I? I didn't ask him
directly, though I joked about it in the usual detached office banter way, and
I wouldn't expect he'd have got it diagnosed anyway. It probably wasn't
serious enough to go to a hospital. But surely it _had_ to be swine flu,
right? So I press 1.

I wouldn't do that, but I'm sure many people would.

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JacobAldridge
I don't see that this study or analysis takes into account that a person with
the swine flu _also_ knows 290 people. So all 290 of them would answer yes.

Multiplying out 290 x the 290 people those people know to give some impressive
number ignores the possibility you might actually need to be dividing.

My math and probability analysis may be dodgy, but I hope my point is made:
simply knowing how many people know someone in a category doesn't give any
meaningful data about how many people are in the category.

