If you open a Borenstein class on YouTube, you may end up on comments like this :
“A meta-analysis is NOT science. It is meaningless garbage for people too lazy and too stupid to do their own randomized clinical study.”
Don’t get me wrong, this is more interesting that it seems at first glance. One of the goal of empirical science is actually to estimate effect size and so the first sentence does not make any sense of course. The second part of the second sentence comes from a hater that probably spent countless hours doing interesting and costly clinical studies that failed to reach significance (welcome to Science dude). But the first part of the second sentence is interesting as it contains the adjective “meaningless” and it is true that, recently, medical and social sciences are received severe critics from top experts (including the famous « Why Most Published Research Findings Are False ») concluding that results of many findings and thus of meta-analysis may be really difficult to interpret if not uninterpretable.