Comment on: “A Critique of the Parapsychological Random Number Generator Meta-Analyses of Radin and Nelson” by Martin Schub

Authors: Scargle J.D. Journal: Journal of Scientific Exploration Publication date: 2006 Keywords: meta-analysis, random number generator, mind-matter interaction, critiques
Journal of Scientific Exploration

I would like to reiterate the point of my JSE paper (Scargle, 2000), namely the Rosenthal formula for assessing the potential influence of publication bias on meta-analyses is simply wrong. Its idea is to estimate the number of papers, unpublished as a result of publication bias, that would be consistent with the positive results of a meta-analysis being merely a statistical fluke. The starting equation of Rosenthal’s analysis postulates that the z-values of the papers in the filedrawer are normally distributed, with zero mean. This is in direct contradiction to the definition of the filedrawer as a biased repository of papers with smaller-than-average z-values. The mistake that many have made is to think of the filedrawer as unbiased, and that its effect is merely to statistically dilute the effects of the meta-analytic results. But publication bias is postulated to be biased.
A simple thought experiment shows that publication bias resulting in approximately equal numbers of published and unpublished papers could very easily explain the positive result of any meta-analysis. Simply construct a set of
hypothetical unpublished papers equal in number to those in the meta-analysis, with z-values equal to the negatives of those in the meta-analysis. If the metaanalysis had a positive mean z, the z-values in this set would be smaller on average than those in the meta-analysis, and their distribution would not be unreasonable to find as the result of a publication-based bias in favor of smaller z-values. Combining this hypothetical filedrawer with the studies in the metaanalysis results in a data set with zero mean z, by construction. Hence any logic that results in the claim that a huge number of papers must be languishing in the filedrawer must be wrong.
In this important paper, Martin Schub makes some comments relevant to fixing up Rosenthal-type estimates, but the above argument places a better, direct upper limit on how big the filedrawer must be. (Of course it could be, but need not be, much larger.)

Featured articles

Links:ブランドコピー高い品質など世界中有名なブランドレプリカを格安で通販しております。N級品ブランドコピーは 業界で最高な品質に挑戦します!激安 ルイヴィトンバッグレプリカ,ルイヴィトンバッグ ブランドコピー激安財布バッグ、ブランドコピー通販 スーパーコピー激安 財布, ブランドコピー激安代引き楽天市場。