February, 2003
© 2000, 2001, 2003 Scott S. Emerson, M.D., Ph.D.
The statistical power associated with a test design is found
by integrating the sampling density under particular alternative
hypotheses.
Statistical power (1 - type II error) is the probability of
observing a test statistic (estimate of treatment effect)
more extreme than the critical value when the alternative
hypothesis is true.
·Varies with the particular alternative
·In a two-sided test we consider one-sided power
-lower power and/or
-upper power