Will a fluoride mouthwash used after brushing reduce cavities? Twenty sets of twins were used to investigate this question. One member of each set of twins used the mouthwash after brushing, and the other did not. After six months, the difference in the number of cavities for those using the mouthwash was compared with the number of cavities for those who did not use the mouthwash. This experiment uses:
A)random placeboes.
B)double blinding.
C)double replication.
D)a matched pairs design.

Question

Quizplus · Accepted Answer

This experiment uses a matched pairs design because each set of twins is paired together, with one member using the mouthwash and the other not using it. This controls for genetic and environmental factors that could affect each twin's cavity risk.

Will a Fluoride Mouthwash Used After Brushing Reduce Cavities? Twenty