| The paired t-test is a t-test
that is used when the test units
can be paired. For example, the blood pressure
of five patients was tested before and after
a medication:
Patient |
Before |
After |
D |
| Andrew |
120 |
110 |
10 |
| Bill |
135 |
115 |
20 |
| Charles |
110 |
110 |
0 |
| David |
140 |
135 |
5 |
| Eric |
115 |
110 |
5 |
A Two Sample t test would show no significant
difference in the 'before' and 'after' results
because the difference between individuals
masks the 'before' and 'after' difference.
The paired test involves carrying out a
One Sample t-test on the differences. Despite
the variation between individuals the 'after'
blood pressure is generally lower.
See also Two
Sample t-Test.
|
