tag:blogger.com,1999:blog-987850932434001559.post6394556782198588245..comments2021-01-16T14:45:57.581+01:00Comments on The 20% Statistician: The p-value misconception eradication challengeDaniel Lakenshttp://www.blogger.com/profile/18143834258497875354noreply@blogger.comBlogger1125tag:blogger.com,1999:blog-987850932434001559.post-72235992385011960052020-10-21T15:43:28.000+02:002020-10-21T15:43:28.000+02:00Daniel-
Thanks as always for your work. I don’t h...Daniel-<br /><br />Thanks as always for your work. I don’t have a lesson of my own to offer, but I did have a comment on a small part of your first assignment that I think could be problematic. <br /><br />On page 2 of the posted version of lesson 1.1, you write about the first figure “There is a horizontal red dotted line that indicates an alpha of 5% (located at a frequency of 100.000*0.05 = 5000)”. But that seems like a confusing or misleading statement. First, since the line indicates a Y value, it must be a frequency of observed outcomes for p; a line showing alpha would have to indicate an X value. And even given that the line indicates the expected frequency of outcomes, it's the expectation *under the null hypothesis*, which is not explained here. More importantly, though, even if you do mean that the line will show the expected height of the bars under the null hypothesis, the only reason that you can use N*0.05 to predict that height is that you’ve divided the distribution into 20 bars - it’s not because alpha is 0.05. If you’d chosen to divide the graph into increments of 0.01 (as you do later), the height of the red line would be N*0.01 despite alpha being 0.05 (but now there would be five bars in the alpha region instead of just one). So the height of the line is based on the number of divisions, not alpha.<br /><br />Does that critique make sense? I can try to explain more fully if not.<br /><br />Cheers,<br />AlistairAlistair Cullumhttps://www.blogger.com/profile/16193690419324782781noreply@blogger.com