February, 2003
© 2000, 2001, 2003 Scott S. Emerson, M.D., Ph.D.
The type I error associated with a test design is found
by integrating the sampling density under the null
hypothesis.
Type 1 error (size of test) is the probability of observing
a test statistic (estimate of treatment effect) more extreme than the
critical value when the null hypothesis is true.