tag:blogger.com,1999:blog-7890764972166411105.post6696239500276817074..comments2024-03-28T12:45:41.494+01:00Comments on Nick Brown's blog: Old stereotypesNick Brownhttp://www.blogger.com/profile/00172030184497186082noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-7890764972166411105.post-65096305828099270872016-07-09T20:59:44.368+02:002016-07-09T20:59:44.368+02:00Remember our sample sizes: nHigh = 18, nLow = 19, ...<i>Remember our sample sizes: nHigh = 18, nLow = 19, nControl = 18. And the measure of warmth was the means of three items on a 1-9 scale. So the possible total warmth scores across the 18 or 19 participants, when you add up the three-item means, were (18.000, 18.333, 18.666, ..., 143.666, 144.000) for High and Control, and (18.000, 18.333, 18.666, ..., 170.666, 171.000) for Low.</i><br /><br />Nick, this first set of possible total warmth scores -- (18.000, 18.333, 18.666, ..., 143.666, 144.000) -- seems a bit off. Don't you want (18.000, 18.333, 18.666, ..., 161.666, 162.000)?John Bullockhttp://johnbullock.orgnoreply@blogger.comtag:blogger.com,1999:blog-7890764972166411105.post-41754883261671573312016-07-05T20:51:41.241+02:002016-07-05T20:51:41.241+02:00For what it is worth, the statistics from the main...For what it is worth, the statistics from the main effect ANOVA also do not seem to match the reported means and standard deviations; although the result is still significant. Using Nick's calculations of the sample sizes for each condition, one can compute MSb = 3.686269091 and MSw = 0.988803846, so F=MSb/MSw = 3.728008447, which gives p=0.03069. The original paper reported F=3.93.<br /><br />A quick check on the numbers does not suggest that this could be a rounding error mistake (although maybe I was not creative enough). It seems like the paper is full of sloppy work all the way around. <br /><br />The correction posted on PubPeer only changes the t-statistics, but leaves the reported means and standard deviations unchanged, so there is still a minor discrepancy. Greg Francisnoreply@blogger.comtag:blogger.com,1999:blog-7890764972166411105.post-77553619050487345152016-07-04T20:30:23.255+02:002016-07-04T20:30:23.255+02:00I looked up the article and it starts with a poem....I looked up the article and it starts with a poem. I think that about says it all.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-7890764972166411105.post-64276225319860553662016-07-04T19:33:13.626+02:002016-07-04T19:33:13.626+02:00So how did they get the ultra-low p-values?
Maybe...So how did they get the ultra-low p-values?<br /><br />Maybe they *did* run paired t-tests, incorrectly? But that can't be possible because the n's were inconsistent across groups.<br /><br />So what on earth happened?Neuroskeptichttps://www.blogger.com/profile/06647064768789308157noreply@blogger.comtag:blogger.com,1999:blog-7890764972166411105.post-57714254817279071442016-07-04T15:27:31.414+02:002016-07-04T15:27:31.414+02:00Yep - if you look at the comments on Gelman's ...Yep - if you look at the comments on Gelman's blog you'll see that this issue was first brought to his attention by someone signing themselves as "Nick" (http://andrewgelman.com/2016/01/26/more-power-posing/#comment-261113). For a variety of reasons (principally the desire to get the GRIM preprint out the door, before demonstrating the technique as here), I just didn't get round to blogging it until now, although I drafted most of this post several months ago.Nick Brownhttps://www.blogger.com/profile/18266307287741345798noreply@blogger.comtag:blogger.com,1999:blog-7890764972166411105.post-40094800120539128922016-07-04T14:43:24.568+02:002016-07-04T14:43:24.568+02:00This was already noted by Andrew Gelman; there'...This was already noted by Andrew Gelman; there's a PubPeer conversation about it: https://pubpeer.com/publications/E043DD982C3CC7F4B2CB4980522684Simon Columbushttp://simoncolumbus.comnoreply@blogger.com