What is a characteristic of double-blind trials?

• A. Participants know which treatment they are receiving
• B. Only researchers are aware of the treatment allocation
• C. Neither the participants nor the researchers know the treatment allocation
• D. External auditors oversee treatment allocation

Answer: (C)

Double-blind trials are designed to eliminate bias in research by ensuring that both the participants and the researchers are unaware of which treatment is being administered. This method helps to prevent any preconceived notions or expectations from influencing the outcomes of the study.

When neither the participants nor the researchers know the treatment allocation, it creates a situation where any effects observed can be attributed to the treatment itself rather than psychological factors or bias introduced by knowing which treatment is being given. This is particularly important in clinical trials where the placebo effect could skew results if participants are aware of their treatment.

In summary, the key characteristic of double-blind trials is this dual level of blindness, which is integral to maintaining the integrity of the study and ensuring unbiased results.