T-Tests

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

Watch our videos on how to perform a two-sample t-test, or paired t-test and Wilcoxon matched-pairs test.

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.