Twenty students agreed to participate in a study on colds. Ten were randomly assigned to receive vitamin C, and the remaining 10 received a tablet that looked and tasted like vitamin C but in fact contained only sugar and flavoring. The students did not know whether they were taking vitamin C or not, but the investigators did.
The students were followed for 2 months to see who came down with a cold and who didn't. Explain whether each of the following terms applies to this randomized experiment.
a. Placebo.
b. Single-blind.
c. Double-blind.
d. Matched pairs.
e. Repeated measures.
f. Replication.