The power of sensory discrimination methods used in replicated difference and preference tests

Research on the power of discrimination methods in difference and preferenc e tests has both theoretical and practical significance. Power is important to evaluate the sensitivities of tests and determine sample size. Ennis an d Bi (1998, 1999) proposed the beta-binomial distribution to model replicat ed difference and preference tests with inter-trial variation and analyzed in general the power of the tests. In this paper, the power of discriminati on methods for replicated difference and preference tests is discussed furt her. The equations for calculating power for methods based on the BE model are given. Examples with tables and charts for calculating and comparing th e power of the methods are also given.