Unpaired and Paired Two-sample t-tests
Two-sample t-tests for a difference in mean involve independent samples, paired samples and overlapping samples. Paired t-tests are a form of blocking, and have greater power than unpaired tests when the paired units are similar with respect to "noise factors" that are independent of membership in the two groups being compared. In a different context, paired t-tests can be used to reduce the effects of confounding factors in an observational study.
Read more about this topic: Student's t-test
Famous quotes containing the word paired:
“The paired butterflies are already yellow with August
Over the grass in the West garden;
They hurt me. I grow older.”
—Li Po (701–762)