Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
A double-blind study refers to a research design where both the participants and the researchers are unaware of who is receiving the treatment or placebo. This helps eliminate bias and ensures more accurate results.
The placebo effect occurs when a participant's belief in receiving treatment leads to an improvement in symptoms, even if they received an inactive substance. This highlights how our mind can influence our body's response.
Randomization: Randomization refers to assigning participants randomly to different groups (treatment or control) in order to reduce bias and ensure that each group is representative of the larger population being studied.
In a double-blind study, the control group receives either no treatment or a placebo, allowing researchers to compare it with the group receiving the actual treatment. The control group provides a baseline against which changes can be measured.