75 subjects divided into 4 groups, so about 19 people per group.<p>Suppose the study was studying the effect of coin tosses per group.  The standard deviation is sqrt(19)&#x2F;19 or about 23%.  And that is only one sigma.<p>So we might also conclude that those who flip heads are &lt;insert effect here&gt; than those who flip tails.   Is anyone really surprised that the reproducibility study [1] found reproducibility comparable that of a coin toss (to about one sigma)?<p>[1] <a href="http:&#x2F;&#x2F;www.nature.com&#x2F;news&#x2F;over-half-of-psychology-studies-fail-reproducibility-test-1.18248" rel="nofollow">http:&#x2F;&#x2F;www.nature.com&#x2F;news&#x2F;over-half-of-psychology-studies-f...</a>