A "double-blind" study is a research method used to eliminate bias. In this setup, neither the participants nor the researchers know who is receiving the treatment or the placebo. This helps ensure that the results are not influenced by expectations or preconceived notions. This approach is commonly used in clinical trials, especially in testing new medications. By keeping both parties unaware, researchers can obtain more reliable data about the effectiveness of the treatment, leading to more accurate conclusions about its benefits and risks.