94 CHAPTER 6 Hypothesis Testing
- A vaccine against type III group B Streptococcus (GBS) was tested on 20
healthy volunteers. Table 6.6 shows the results on the antibodies before
and after immunization.
(a) What type of test would you apply?
(b) Would a bootstrap test be better than a paired t - test?
(c) Should the test be one - sided or two - sided? Provide justifi cation for
your answer.
Table 6.6
Antibody Changes from Vaccine Given to
20 Healthy Volunteers
Antibody concentration to type III GBS
Volunteer
no.Before
immunizationAfter
immunization
1 0.4 0.4
2 0.4 0.6
3 0.5 0.8
4 0.5 0.6
5 0.4 0.5
6 0.5 0.5
7 0.5 0.6
8 0.4 0.5
9 0.4 0.4
10 0.6 0.7
11 0.7 10.2
12 0.7 1.1
13 0.8 0.9
14 0.9 1.2
15 1.0 1.9
16 1.0 0.9
17 1.1 2.1
18 1.0 2.0
19 1.6 8.1
20 2.1 3.8