Question

1. The concept of control is used in two different ways:

     A. Control provides a standard of comparison

     B. Control reduces variability

     In your own words, explain the meaning of both uses of control and give a

     hypothetical example of each.

Answer 1

A control group is very important in hypothetical testing problem. Because it can be used as standard one to compare other groups. For example for a drug test let say A,B,C and placebo. Placebo is treated as controlled one. Since new drug A, B and C can be effectively compare with placebo and thus made placebo is a standard of comparison, similarly this will help to reduce variability. We are unware about the variability of new drugs but can be controlled or reducible all variability just by adding a known control group as placebo.