Aim/Intent | New generalizable knowledge | Comparison, choice, reassurance, spur change | Improvement of processes and outcomes |

Observability of testing | Blinded or controlled | No test, observe current performance | Tests are observable |

Bias | Design to eliminate bias | Measure and adjust to reduce bias | Accept consistent bias |

Sample size | As many as possible for sufficient power | Obtain 100% of available data | ‘Just enough’ data with sequential samples |

Flexibility of hypothesis | Fixed hypothesis | No hypothesis | Hypotheses are flexible and change as learning takes place |

Testing strategy | One test or several large tests | No tests | Sequential tests |

Determining if a change is an improvement | Hypothesis testing, statistics (eg, t-test, χ^{2}, ANOVA) | No change focus | Statistical process control charts |