"Studies have shown"

How much authority do we give a statement when it is prefaced by the phrase "studies have shown?" Anyone can say "studies have shown" something and no one really doubts what they say. Usually when someone says that, there are no actual studies that are referred to. If there was a study, who conducted the study? What control group did they use? What were their methods for conducting the study? What presuppositions might they have personally that would taint their results? What was the purpose of the study? Very importantly, who funded the study? Where was the study done, and did it have enough variables to achieve accurate results? I no longer lend much credit to someone who says "studies have shown" (I am referring mostly to people in the media) because when someone refers to a "study" they are usually using that study to enforce something that they already believe. Next time you hear someone say "studies have shown," think about what their reason is for quoting the study and see if they mention anything about the actual study, or just mention the results.