Which term describes the design feature that neither researchers nor participants know treatment allocation, helping prevent bias?

Which term describes the design feature that neither researchers nor participants know treatment allocation, helping prevent bias?

• A. Double blind
• B. Single blind
• C. Triple blind
• D. Open label

Answer: (A)

Blinding in trials is about hiding who gets which treatment to reduce bias. When neither the participants nor the researchers know the treatment allocation, this prevents expectations from influencing behavior, treatment administration, or outcome assessment. This setup is called double blind. If only participants are unaware while researchers know, that’s single blind. If additional people like outcome assessors or data analysts are also kept unaware, that’s sometimes referred to as triple blind. Open label means no blinding at all, so everyone knows who gets what. Given the description—both researchers and participants don’t know the allocation—the term that fits is double blind. This design helps ensure that biases from either side don’t color responses or judgments, keeping the results more trustworthy.

Blinding in trials is about hiding who gets which treatment to reduce bias. When neither the participants nor the researchers know the treatment allocation, this prevents expectations from influencing behavior, treatment administration, or outcome assessment. This setup is called double blind.

If only participants are unaware while researchers know, that’s single blind. If additional people like outcome assessors or data analysts are also kept unaware, that’s sometimes referred to as triple blind. Open label means no blinding at all, so everyone knows who gets what.

Given the description—both researchers and participants don’t know the allocation—the term that fits is double blind. This design helps ensure that biases from either side don’t color responses or judgments, keeping the results more trustworthy.