Final answer:
A double-blind study is a research method where neither the participants nor the researchers know who is receiving the active treatment or placebo, thus minimizing bias and enhancing the validity of the results.
Step-by-step explanation:
A study in which neither the subjects participating in the research nor the scientists conducting the research know which subjects are receiving treatment and which are getting a placebo is known as a double-blind study. This helps in preventing bias in results as neither party has knowledge that could potentially influence the outcome. The Salk vaccine trial is one notable example of a successful double-blind experiment, now considered the gold standard in clinical research.
By ensuring that neither the researchers nor the subjects know which group the subjects have been placed in, the double-blind method reduces both experimenter bias and the effects of participant expectations, including the placebo effect. The placebo effect occurs when the belief in the treatment, rather than the treatment itself, leads to a perceived or actual improvement in the participant's condition. Using this method, researchers aim to obtain more accurate data