Answer:
Double blind experiment
Step-by-step explanation:
Double blind experiment is used in experimental setting to avoid impartial judgement or error from biases. It involves the physician and the patient not being aware of who is getting the drug. In a study where the effect of a new drug is being tested, the medical researcher interacts with those participating in the study without knowing who is getting the real drugs and those getting the placebo [the substances that look like the real drug being used but are not]