Double-Blind Research Design

Most experiments in psychology employ a procedure in which information about the purpose and hypothesis of the study is kept secret from participants until after the experiment is over. This is often referred to as a “blind” experiment, and it helps ensure that a research participant will not be biased either intentionally or unintentionally. It is also important to take into consideration the risk of experimenter bias, where knowledge of the purpose and hypothesis of the study might cause the experimenter to be biased and thus unintentionally behave in ways that systematically cause participants to perform differently on the variables being measured.

Clinician and participant bias must also be avoided when conducting randomized controlled trials. Clinician bias occurs when the clinicians administering treatment in a randomized ...