Answer:
Placebo
Explanation:
A placebo group is "an inactive substance or treatment that cannot be distinguished from a real, active substance or treatment"
Fro any experiment, "subjects respond differently after they receive a treatment, even if the treatment is neutral". When we have a neutral treatment that has no effect on the dependent variable is called a "placebo".
And is important to used when we want to find significant effects on any treatment in a population selected. And the common procedure that use a placebo group is the ANOVA of 1 or 2 ways.
