An investigation to test an intervention in which neither the patient nor the doctor knows if the patient is receiving active medication or a placebo.
An experiment designed such that neither the subject nor the investigator is aware of the treatment given to the subject.
Experiment in which neither the investigator nor the subject knows whether the subject received the experimental variable (e.g., a drag) or a placebo, thus eliminating any influence such knowledge might have on the reactions of the subject and the expectations or interpretations of the investigator.
A way of controlling against experimental bias by ensuring that neither the researchers nor the subjects know which treatment any subject is receiving.
A modality of research conception or establishment in which the participants, as well as the researchers, are ignorant of the specific individuals allocated to each cohort until after the findings have been scrutinized.