single-blind

Definition of single-blind study
National Cancer Institute

single-blind study

(SING-gul-blind STUH-dee)
A type of clinical trial in which only the researcher doing the study knows which treatment or intervention the participant is receiving until the trial is over. A single-blind study makes results of the study less likely to be biased. This means that the results are less likely to be affected by factors that are not related to the treatment or intervention being tested.

Source: NCI Dictionary of Cancer Terms