comment from post 3

I agree that random sampling is important but apparently, even with random sampling, there can still be biases. "Though randomization is an important first step for ensuring research  validity, randomized studies are not always unbiased or completely reliable. As Ioannidis emphasized, though “ ‘randomized controlled trials,’ which compare how  one group responds to a treatment against how an identical group fares without  the treatment, had long been considered nearly unshakable evidence…they, too, ended up being wrong some of the  time.” Randomized trials are not exempt from errors and biases. The wording of  questions, how studies are designed, which measurements are chosen for analysis,  and how results are presented can all influence the validity of a study."  It seems extremely difficult to make a truly unbiased research study. Do you agree?

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