or "control subjects"
are individuals who participate in a research
study and receive a standard treatment to be compared with
the experimental treatment.
For example, in a research study to evaluate
whether a new drug improves memory, researchers may assign
the subjects randomly into two groups, the experimental group
and the control group. Subjects in the experimental group
will be given the new drug, while subjects in the control
group will be given an existing drug (or perhaps a placebo).
Later, the researchers will give a memory test to all subjects.
If the subjects in given the new drug perform better than
control subjects, this will be evidence that the new drug
is effective. On the other hand, if subjects given the new
drug perform no better (or even worse) than control subjects,
this will be evidence that the new drug is ineffective or
no better than existing treatments.
by Catherine E. Myers. Copyright © 2006 Memory Loss and the Brain