What term is used to describe participants who don't know whether they are in an experimental group or a placebo group?

Question

Quizplus · Accepted Answer

Participants who don't know whether they are in an experimental group or a placebo group are referred to as "blind." This helps to prevent bias in the results of the study, as participants who know they are in the experimental group may behave differently than those who know they are in the placebo group.

What Term Is Used to Describe Participants Who Don't Know