An experiment in which either the subjects or those who interact with them and measure responses know which treatment was given, but not both, is described as what?

An experiment in which either the subjects or those who interact with them and measure responses know which treatment was given, but not both, is described as what?

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

Answer: (A)

Blinding helps reduce bias by keeping expectations from shaping the results. In a single-blind design, only one group is unaware of which treatment was assigned. The scenario describes exactly that: either the participants or the people who interact with them and measure responses know the treatment, but not both. That limited level of blinding fits single-blind. If both groups were unaware, it would be double-blind; if even those analyzing the data were unaware, it would be triple-blind. Open-label means no blinding at all.

Blinding helps reduce bias by keeping expectations from shaping the results. In a single-blind design, only one group is unaware of which treatment was assigned. The scenario describes exactly that: either the participants or the people who interact with them and measure responses know the treatment, but not both. That limited level of blinding fits single-blind. If both groups were unaware, it would be double-blind; if even those analyzing the data were unaware, it would be triple-blind. Open-label means no blinding at all.