MCAT® ExamPsychological, Social, and Biological Foundations of BehaviorEasy
A research team is investigating the effectiveness of a new therapy for anxiety disorders. They randomly assign participants to either a treatment group receiving the new therapy or a control group receiving a placebo. To ensure that neither the participants nor the researchers administering the therapy know who is receiving which treatment, which of the following research designs is being employed?
- ACorrelational study
- BDouble-blind study
- CLongitudinal study
- DSingle-blind study
Show answer & explanationAnswer & explanation
Correct answer: B. Double-blind study
A double-blind study is a research design where both the participants and the researchers are unaware of who is receiving the treatment and who is receiving the placebo. This helps to minimize bias.
Why the other options are wrong
- A. A correlational study examines relationships between variables without manipulation, not a blinding technique.
- C. A longitudinal study observes the same subjects over an extended period, which is not a blinding method.
- D. A single-blind study only conceals the treatment assignment from the participants, not the researchers.
Double-blind Study
A research design in which neither the participants nor the experimenters know who is receiving a particular treatment.
- Minimizes bias from participant expectations (placebo effect)
- Minimizes bias from experimenter expectations (observer-expectancy effect)
- Often used in clinical trials to test drug efficacy
Memory trick: Don't know, don't show, biases can't grow.