If you give 100 sick people tablets similar to Echinacea but with no herb (called a placebo), and do not tell them whether they are receiving the placebo or the Echinacea tablet, what kind of control would this be?
A)A positive control, since you are expecting a change to happen in this control group
B)A negative control, since you are expecting no change to happen in this control group
C)A blind control, since the sick people do not know whether they are receiving the placebo or the Echinacea
D)Both B and C are correct

Question

Quizplus · Accepted Answer

This is an example of a negative control because the placebo is expected to have no effect, thus serving as a baseline to compare against the active treatment (Echinacea). It is also a blind control because the participants do not know whether they are receiving the placebo or the actual treatment, which helps to eliminate bias in the results.

If You Give 100 Sick People Tablets Similar to Echinacea