Question

In Exercises 33–36, identify which of these designs is most appropriate for the given experiment: completely randomized design, randomized block design, or matched pairs design

HIV Vaccine The HIV Trials Network is conducting a study to test the effectiveness of two different experimental HIV vaccines. Subjects will consist of 80 pairs of twins. For each pair of twins, one of the subjects will be treated with the DNA vaccine and the other twin will be treated with the adenoviral vector vaccine

Short answer

The most appropriate experimental design for the given data is a matched pairs design.

Step-by-step solution

Given information

The study has a number of twins wherein one of each pair receives the DNA vaccine, and the other receives the adenoviral vector vaccine.

Types of experimental designs

Matched-pairs design: Subjects having the same features are clustered into pairs, and then the treatment is applied to one of each pair.

Randomized block design: Subjects with the same features are collected together in one block.

Completely Randomized design: All subjects have an equal chance of getting the treatment under consideration.

Identification of the type of design

As pairs of twins are used for the study, where one twin from each pair receives the DNA vaccine and the other twin receives the adenoviral viral vaccine, the matched – pairs design is the most appropriate.