Definition: A double-blind study exists if both the researcher and the participants are not aware of which treatment each participant is receiving. For example, in a study of a particular medication, a placebo is usually given to half the participants and the actual medication of interest to the remaining participants. In a double-blind experiment, neither the researchers nor the participants know who received the placebo and who received the medication. Double-blind studies are conducted to prevent bias on the part of the researchers and the participants.
Common Misspellings: double blind study