t - tests.
Korosteleva, O., & Song, B. (2018). t - tests. In B. B. Frey (Ed.), The SAGE encyclopedia of educational research, measurement, and evaluation (pp. 1652-1654). SAGE.
The t - test is used with the t distribution to examine differences between two groups when the variances are not known. This section describes the three different t - tests and when each of them are used.