From: t-tests, non-parametric tests, and large studies—a paradox of statistical practice?

Number of subjects in each group | |||||||
---|---|---|---|---|---|---|---|

10 | 25 | 50 | 100 | 250 | 500 | 1000 | |

Gamma distributions | |||||||

t-test | 4.01 | 4.71 | 4.91 | 4.98 | 4.95 | 4.99 | 4.97 |

WMW test | 9.47 | 18.0 | 28.9 | 41.6 | 56.9 | 66.3 | 74.7 |

Lognormal distributions | |||||||

t-test | 4.20 | 4.69 | 4.83 | 4.89 | 4.95 | 4.92 | 4.98 |

WMW test | 5.21 | 6.99 | 9.63 | 14.4 | 26.5 | 39.7 | 54.3 |