# Similar test

A statistical test for testing a compound hypothesis $H_0\colon\theta\in\Theta_0$ against a compound alternative $H_1\colon\theta\in\Theta_1$ ($\Theta_0\cap\Theta_1=\emptyset$), the power function (cf. Power function of a test) of which takes on $\Theta_0$ the same, fixed, value from the interval $(0,1)$.