patients with alzheimers disease are randomly divided into t

patients with alzheimer\'s disease are randomly divided into two groups. one group is given a new drug, and the other is given a placebo. After six months they are given a memory test to see whether the new drug fights Alzheimer\'s better than a placebo.

is it observational study or controlled experiment?

Solution

It is a controlled experiment because we set two groups to see whether the new drug fights Alzheimer\'s better than a placebo.