http://wmbriggs.com/blog/2007/12/30/hurricanes-have-not-increased-misuse-of-running-means/ "All manner of statistical analyses cheerfully undertaken." Fri, 21 Nov 2008 10:28:55 +0000 http://wordpress.org/?v=2.3.3 http://wmbriggs.com/blog/2007/12/30/hurricanes-have-not-increased-misuse-of-running-means/#comment-136 William M. Briggs, Statistician » AMS conference report: day 3 Wed, 23 Jan 2008 17:17:18 +0000 http://wmbriggs.com/blog/2007/12/30/hurricanes-have-not-increased-misuse-of-running-means/#comment-136 [...] This looks like hurricane numbers through time, doesn’t it? Well, it’s not: it’s just a bunch of random numbers with no correlation from “year” to “year”, overplotted with a 9-year running mean. I wrote about this earlier: using running means on count data that actually has no correlation far too easily can show you trends (to the eye, anyway) where they do not exist. But you see these kinds of plots all the time, even in the best of the best journals, like Science and Nature. You cannot show these kind of plots without some kind of measure of the uncertainty that the trend is real, but it happens all the time, and people make decisions using these plots assuming such trends are real. [...] […] This looks like hurricane numbers through time, doesn’t it? Well, it’s not: it’s just a bunch of random numbers with no correlation from “year” to “year”, overplotted with a 9-year running mean. I wrote about this earlier: using running means on count data that actually has no correlation far too easily can show you trends (to the eye, anyway) where they do not exist. But you see these kinds of plots all the time, even in the best of the best journals, like Science and Nature. You cannot show these kind of plots without some kind of measure of the uncertainty that the trend is real, but it happens all the time, and people make decisions using these plots assuming such trends are real. […]

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