AP PSYCHOLOGY

Detailed explanation-1: -A type of clinical trial in which neither the participants nor the researcher knows which treatment or intervention participants are receiving until the clinical trial is over. This makes results of the study less likely to be biased.

Detailed explanation-2: -Therefore, both research participants and researchers are blind to this information. Double-blind studies help in reducing the biases like the placebo effect, experimenter bias, and experimenter expectancy effect that hinder the results and conclusions of the study.

Detailed explanation-3: -In a double-blind study, both participants and experimenters are blinded. In a triple-blind study, the assignment is hidden not only from participants and experimenters, but also from the researchers analyzing the data.

Detailed explanation-4: -Answer and Explanation: The correct answer is b. double-blind.

Detailed explanation-5: -Single-blind usually means that the research participant is not told of the treatment assignment. Double-blind usually means that the research participant, investigator, study coordinator/nurse, study sponsor, and in some cases the data analyst are kept unaware of the treatment assignment.