In a study of a new vaccine, participants do not know which injection they received, but the nurses administering the shots and recording side effects do know.
This experiment is best described as
- Acheck_circle
Single-blind
- B
Double-blind
- C
Placebo-controlled but not blinded
- D
Open-label
Explanation
Only one party (subjects) is blind to assignment. The nurses who record outcomes are not, so this is single-blind, leaving room for evaluator bias.