In a double-blind randomized clinical trial, neither the investigators nor the subjects know who receives the active pharmacological agent.Scientists use a single-blind test to see if people like the new cola or the old one.The company did a double-blind study to prove their new vitamin pill is good.To eliminate ascertainment bias and analytical preconceptions, a triple-blind design ensures that patients, clinicians, and the data monitoring committee analyzing the statistical outcomes remain completely unaware of treatment assignments.

