title: What's it mean when researchers say a medical study is controlled? Aren't all studies controlled in some way? And while you're at it, what's randomized mean?
mesh_terms: D006801:Humans; D010919:Placebos / Q000627:therapeutic use; D011897:Random Allocation; D016032:Randomized Controlled Trials as Topic / Q000379:methods*
chemical_list: D010919:Placebos