Double-Blind

A double-blind study is a test or trial in which information that could affect the test results is withheld from both the tested subject and the tester in order to avoid influencing the final results. In a classic example, a patient is invited to participate in a clinical trial for a drug. The participant is given one of two versions of the medicine: one containing the active components and another containing just a placebo. If the trial is double-blind, neither the participant nor the researcher will know which is which, thus allowing the experiment to develop without external influences.