It's an extremely important question to ask and especially when someone dumps a wall of text and a ton of studies on you that all support one viewpoint:
* Have you also evaluated studies that don't support this?
* If not, why not? Are you only looking for studies that support what you want to prove?
* If you have also looked at studies showing negative results, why have you decided not to include them here?
* Have you also evaluated studies that don't support this?
* If not, why not? Are you only looking for studies that support what you want to prove?
* If you have also looked at studies showing negative results, why have you decided not to include them here?