Comments on: Data Dredging for Dollars, EPA Style http://www.masterresource.org/2010/03/data-dredging-for-dollars-epa-style/ A free-market energy blog Sat, 11 Feb 2012 00:44:05 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: Andrew http://www.masterresource.org/2010/03/data-dredging-for-dollars-epa-style/comment-page-1/#comment-8973 Andrew Mon, 29 Mar 2010 16:34:01 +0000 http://www.masterresource.org/?p=8401#comment-8973 It's even worse than that, Ken. Imagine if people insisted that there must be a "heads" cluster on a part of the map with a lot of pennies, because more heads are there than other places. Sure, and there are more tails there also. It should hardly surprise anyone that there are "lumpy" distributions in epidemiology, since there are "lumpy" distributions of human population in the first place. I imagine that NY City has the most cancer cases in the country, or close to it. I don't think some analysts even bother to normalize for population density. It’s even worse than that, Ken. Imagine if people insisted that there must be a “heads” cluster on a part of the map with a lot of pennies, because more heads are there than other places. Sure, and there are more tails there also. It should hardly surprise anyone that there are “lumpy” distributions in epidemiology, since there are “lumpy” distributions of human population in the first place. I imagine that NY City has the most cancer cases in the country, or close to it.

I don’t think some analysts even bother to normalize for population density.

]]> By: Kenneth P. Green http://www.masterresource.org/2010/03/data-dredging-for-dollars-epa-style/comment-page-1/#comment-8969 Kenneth P. Green Mon, 29 Mar 2010 14:16:25 +0000 http://www.masterresource.org/?p=8401#comment-8969 Andrew - You're correct in pointing out that people simply don't understand the nature of probability and statistics, a failure easily demonstrated by the continued growth of Lotto revenues, and the continued profitability of casinos. When it comes to things like cancer clusters, or any kind of illness cluster, people simply assume that there must be a cause, not understanding that such things will happen purely by random chance. I try to explain this to people by posing the following challenge to them. First, I get them to agree that flipping a coin is a 50:50 proposition, and that every toss is a unique event, unrelated to previous or future tosses. Then I have them take 1000 pennies, and toss them randomly onto a map. If they then look over the map, they'll find areas with clusters of heads and tails that arise simply through random distribution. Andrew – You’re correct in pointing out that people simply don’t understand the nature of probability and statistics, a failure easily demonstrated by the continued growth of Lotto revenues, and the continued profitability of casinos.

When it comes to things like cancer clusters, or any kind of illness cluster, people simply assume that there must be a cause, not understanding that such things will happen purely by random chance. I try to explain this to people by posing the following challenge to them. First, I get them to agree that flipping a coin is a 50:50 proposition, and that every toss is a unique event, unrelated to previous or future tosses. Then I have them take 1000 pennies, and toss them randomly onto a map. If they then look over the map, they’ll find areas with clusters of heads and tails that arise simply through random distribution.

]]> By: Andrew http://www.masterresource.org/2010/03/data-dredging-for-dollars-epa-style/comment-page-1/#comment-8968 Andrew Mon, 29 Mar 2010 13:15:21 +0000 http://www.masterresource.org/?p=8401#comment-8968 Right now in Florida an effort is under way desperately trying to find a cause for the "cancer cluster" in the Acreage-destroying property values all the way, and probably forcing the rest of us to pay to have them put on our water supply (one-debunked-theory is that their wells are connected). And all because people don't understand randomness. People seem to think that if you found that cancer victims all lived an equal distance apart that would be "random". Hogwash, in fact if I saw people dying fixed distances apart I'd think "serial killer" immediately. The problem is something called "egalitarian bias" http://motls.blogspot.com/2009/04/perceiving-randomness-egalitarian-bias.html Right now in Florida an effort is under way desperately trying to find a cause for the “cancer cluster” in the Acreage-destroying property values all the way, and probably forcing the rest of us to pay to have them put on our water supply (one-debunked-theory is that their wells are connected). And all because people don’t understand randomness. People seem to think that if you found that cancer victims all lived an equal distance apart that would be “random”. Hogwash, in fact if I saw people dying fixed distances apart I’d think “serial killer” immediately.

The problem is something called “egalitarian bias”

http://motls.blogspot.com/2009/04/perceiving-randomness-egalitarian-bias.html

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