**Select menu: Stats | Statistical Tests | One- and two-sample t-tests**

Performs a one- or two-sample t-test. The menu carries out validity checks. If any sample has fewer than 6 values Genstat warns you that the sample size is too small and the test may not be valid. For a two-sample test, Genstat carries out an F-test for equality of variance and prints a warning if there is evidence of unequal variances. For a two-sample t-test you can also choose to calculate the probability using a random permutation test.

- After you have imported your data, from the menu select

**Stats | Statistical Tests | One- and two-sample t-tests**. - Fill in the fields as required then click
**Run**.

You can supply weights to replicate observations by clicking Options. After running, you can save the results by clicking Save.

## Available data

Lists the variates and factors that can be used to supply the data sets and/or groups. The contents may change as you move from one input field to another, so that appropriate types of data structure are listed. Double-click on a name to copy it into the input field, or type the name in directly.

## Test

Specifies the test to be carried out: One-sample, Two-sample, or Paired samples.

## One-sample test

Data variate |
Specifies the name of the variate containing the data. |

Test mean |
Specifies mean for the null hypothesis of a one-sample test. |

## Two-sample test

For a two-sample test you can supply the data in one of two ways using the **Data arrangement** options. You can specify the data as a pair of variates:

Data variate 1 |
Specifies the name of the variate containing the first data sample. |

Data variate 2 |
Specifies the name of the variate containing the second data sample. |

or as a single variate with a factor defining the groups:

Data variate |
Specifies the name of the variate containing the data sample. |

One variate with group factor |
Specifies the name of a factor defining the group membership. |

## Paired samples

For a paired sample t-test you should supply the data as two data variates where the paired observations are stored in the same unit (or row) position within both variates.

Data variate 1 |
Specifies the name of the variate containing the first data sample. |

Data variate 2 |
Specifies the name of the variate containing the second data sample. |

## Confidence limit

Enables you to control the limit for the calculation of a confidence interval. The limit is expressed as a percentage and must be in the range 0-100.

## Type of test

Enables you to choose either a one-sided or two-sided t-test.

## See also

- T-Test Options to control printed output and to perform a random permutation test.
- T-Test Save Options to store the results
- Bootstrap Resampling menu for bootstrapping t-tests