If you don't understand their methodology, you probably shouldn't be attempting to critique it.
There's an implicit assumption in your comment that the methodology is good, and that anyone who criticises it must be unable to see that. Have you ever read the story "The Emperor's New Clothes"?
No. I'm giving the benefit of the doubt to people who are educated professionals in their field who have presented research that likely withstood some level of editorial and peer review....over a random internet commenter who starts their comment with "I don't understand their methodology" and then proceeds to attempt to critique it.
I should have been more clear. By saying "I don't understand their methodology," I was hedging around the statement "their paper does not contain an adequate explanation of their methodology due to the nature of the complex systems they are modeling. By omitting information on how they constructed their controlling variables (and indeed the full scope of what variables they controlled for), the authors (perhaps inadvertently) cast doubt upon the conclusions they draw from their results."
Because there are statistics, and there are bad statistics. Indeed, only professionals are qualified to make studies, but anyone having at least a basic understanding of probabilities and statics can point out a badly thought out one.
The rest of gp's post exhibits good understanding of statistics. I suspect they're actually more qualified than "internet forum commentator". And it's good to be honest about what you do/don't understand, the fault could be in the explanation...
Well... A. Perhaps this “Internet forum commentator” has more relevant experience than you understand, B. You don’t need to have years of scientific study to understand statistics and C. Plenty of bad science gets published every year in journals.
