In a proper double-blind experiment
A)the effects of an active drug treatment are compared with the effects of a placebo
B)neither the subjects nor the experimenters know what treatment the subjects receive until after all the drug tests are completed
C)subjects receive the active drug treatment and then are shifted to the placebo treatment without their being informed of the switch
D)only a and b above

Question

Quizplus · Accepted Answer

In a proper double-blind experiment, both option a and b are correct. The effects of an active drug treatment are compared with the effects of a placebo, and neither the subjects nor the experimenters know what treatment the subjects receive until after all the drug tests are completed. Therefore, the correct choice is D, only a and b above. Option C is incorrect as it describes a single-blind experiment where only the subjects are unaware of the treatment they receive, while the experimenters know which treatment is being given.

In a Proper Double-Blind Experiment