MCAT® ExamCritical Analysis and Reasoning SkillsMedium
A team of medical researchers is conducting a study on the efficacy of a new drug. They are careful to ensure that neither the patients nor the administering clinicians know whether they are receiving the actual drug or a placebo. This experimental design choice is primarily intended to mitigate which two types of bias?
- ASocial desirability bias and experimenter bias
- BSelection bias and confirmation bias
- CObserver bias and participant bias
- DHindsight bias and anchoring bias
Show answer & explanationAnswer & explanation
Correct answer: C. Observer bias and participant bias
A double-blind study, where neither participants nor researchers know who is in the control or experimental group, primarily aims to prevent participant bias (patients' expectations affecting outcomes) and observer bias (researchers' expectations affecting their observations or interpretations).
Why the other options are wrong
- A. Social desirability bias relates to participant self-reporting, and while experimenter bias is related to observer bias, 'participant bias' is a more encompassing term for the patient side of the effect.
- B. While important, selection bias is addressed by randomization, and confirmation bias by objective measures, not primarily by double-blinding.
- D. Hindsight bias relates to past events, and anchoring bias to initial information, neither of which is directly mitigated by double-blinding.
Double-Blind Study
A double-blind study is an experimental procedure in which neither the participants nor the researchers (or those administering the treatment) know who is receiving the particular treatment and who is receiving a placebo.
- Prevents participant expectations from influencing results (participant bias).
- Prevents researcher expectations from influencing results (observer/experimenter bias).
- Enhances the objectivity and internal validity of research findings.
Memory trick: Blinded Eyes Keep Minds From Sway.