Question

A double-blind research design is one in which

a. both the subject and the investigator know what treatment had been administered.
b. only the investigator knows what treatment has been administered.
c. the subject does not know which treatment he/she has been administered.
d. neither the subject nor the investigator knows what treatment had been administered.

Answer 1

A double-blind research design is one in which neither the subject nor the investigator knows what treatment had been administered. This is done to control for experimenter and participant expectations and prevent bias in the outcome of the experiment.

Step-by-step explanation:

A double-blind research design is one in which neither the subject nor the investigator knows what treatment had been administered. In a double-blind study, both the researchers and the participants are blind to group assignments. This is done to control for experimenter and participant expectations and prevent bias in the outcome of the experiment.