noun, plural: manipulated variables
An experiment is designed to see if a newly developed drug is effective in treating patients with cough. Some of the patients were given the drug while others the placebo. To determine if the drug is effective, the recovery of patients taking the drug is monitored and compared against that of the patients taking the placebo. If the patients taking the drug are able to recover faster than the patients taking the placebo, it could mean that the drug is effective against cough. If patients taking the drug and the placebo have the same rate of recovery, the drug may not be an effective treatment for cough.
Compare: independent variable