Inferential Decision | Unknown but True State of the World | |
---|---|---|

H_{0} True | H_{0} False | |

Reject H_{0} | Type I error | Correct decision |

Probability = a | Probability = 1 − b | |

Do not reject H_{0} | Correct decision | Type II error |

Probability = 1 − a | Probability = b |

a, type I error rate; b, type II error rate (1 − b is power).