Answer: blinding
Step-by-step explanation:
- An experimental study in which the experimenter know the experimental procedure but not the participants are in the test groups during the the experiment is known as single blind.
Given: In a clinical trial for a new headache medication, participants are randomly assigned to a treatment group or a placebo group.
They do not know whether they are receiving the medication or a placebo.
⇒ The element of experiment design being used is single blind experiment or blinding.
