Downvoted for not knowing what double blind means.
Wrong answer: Researches who are blind in both eyes only give the medication to participants who are also blind in both eyes, thus making them unable to read the patient information leaflet.
Correct answer: It is a research design in which both the participants and the researchers are unaware of who is receiving the treatment and who is in the control group
There is a little bit of wiggle-room because “double-blind” isn’t fully defined.
It usually means neither the clinician nor the patient know what is being given. But sometimes that is impossible (eg if the comparison is of two types of surgery) so the assessor may be blinded instead. It is also possible to blind the statistician and authors (so they analyse/write up without knowing which treatment is which).
We’ve never got around to making the labels more exact, we just state who is and is not blinded. “Double-blind” and “triple-blind” are often used when two or three parties are blinded but neither term defines exactly who is blinded.
Isn’t it where the testers and testees have no idea which is the placebo during testing? I figured this was at the end