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...

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.