S
Single Blind
In a single blind clinical trial, doctors know which patients are receiving treatment and which are receiving an inactive placebo, but the patients do not. Patients have to wait until the trial is over to find out. This helps reduce the risk of errors, since there is the potential for patients to inadvertently affect the results of the study if they knew. (When neither doctors nor patients know which group received which, that’s known as a double blind trial.)