## SDSS with friends

Posted in Statistics with tags , , , , , , , , on May 4, 2018 by xi'an

When browsing over lunch the April issue of Amstat News, I came upon this page advertising rather loudly the SDSS symposium of next month. And realised that not only it features “perhaps the most prominent statistician to have repeatedly published material written by others without attribution” (a quote from Gelman and Basbøll, 2013, in American Scientist), namely  Ed Wegman, as the guest of honor,  but also one co-author of a retracted Computational Statistics paper [still included in Wegman’s list of publications] as program chair and another co-author from the “Hockey Stick” plagiarised report as plenary speaker. A fairly friendly reunion, then, if “networking” is to be understood this way, except that this is a major conference, supported by ASA and other organisations. Rather shocking, isn’t it?! (The entry also made me realise that the three co-authors were the original editors of WIREs, before Wegman and Said withdrew in 2012.)

## Le Monde on E. Wegman

Posted in Statistics with tags , , , , , , on December 31, 2011 by xi'an

In addition to the solution to the wrong problem, Le Monde of last weekend also dedicated a full page of its Science leaflet to the coverage of Michael Mann’s hockey curve of temperature increase and the hard time he has been given by climato-skeptics since its publication in 1998… The page includes an insert on Ed Wegman’s 2006 [infamous] report for the U.S. Congress, amply documented on Andrew’s blog. And mentions the May 2011 editorial of Nature on the plagiarism investigation. (I reproduce it above as it is not available on the Le Monde website.)

## Le Monde [reverse] rank test

Posted in Statistics with tags , , , , on April 13, 2010 by xi'an

This is the fourth and hopefuly last post about this puzzle. If I translate the problem proposed by Le Monde, it reads as follows

Twenty pupils in the class have different grades that are the integers from 1 to 20. The ten girls in the class are ordered from the best grade to the worst one, while the ten boys in the class are placed from the worst grade to the best one. The absolute differences between the pairs thus formed are computed and sum up. What is the range for this sum?

which is different from what I “read”, where both boys and girls were ranked in increasing order. Of course, “my” reading makes more sense (!) from a statistical point of view, because this defines a rank test for both samples having the same distribution. (The range is then between 10 and 100.) However, the solution to the original problem published in the weekend special edition is that the sum is always equal to 100. The argument is that any number less than 10 is paired with a number larger than 10, thus that the numbers larger than 10 get a positive sign, while the numbers less than 10 always get a negative factor, leading to

$\sum_{i=1}^{10} (10+i) - \sum_{i=1}^{10} i = 10\times 10 = 100.$

Obviously, this result holds for any balanced group of pupils. This is however much less interesting from a statistical perspective.

Ps- I found recently that both writers of the “Affaire de Logique” page in the weekend Le Monde magazine, Elisabeth Busser and Gilles Cohen, are in fact editors of a math fanzine called Tangente. Gilles Cohen wrote a laudatory review of the book, Le Mythe Climatique, by Benoît Rittaud, next to an explanation by Benoît Rittaud of the findings of Ed Wegman and of his Academy of Sciences committee about the hockey stick temperature curve. While the problem with the hockey stick is clear enough, the data being recentred only against recent observations, the explanations given in Tangente are fairly obscure. As a coincidence, Benoît Rittaud just decided to put his blog on hold and to move to a collective climatoskeptic blog called skyfall