Definition
A Blinded Experiment is a study in which information about the test is masked (kept) from the participant, to reduce or eliminate bias until after a trial may be conducted.
Why It Matters
Without blinding, the human tendency toward confirmation bias renders even the most rigorous-looking data unreliable, leading to wasted resources on ineffective drugs or flawed social theories.
Core Concepts
- Single-Blind: The participant does not know if they are in the control or experimental group.
- Double-Blind: Both the participant and the experimenter do not know who is in which group, preventing subtle cues (experimenter bias) from influencing the result.
- Placebo Effect: Using an inactive substance as a control to measure the psychological impact of expectation (Placebo Effect Mechanics).