T Test. The welch s t test which is less restrictive compared to the original student s test. It is often used in hypothesis testing to determine whether a process or treatment actually has an effect on the population of interest or whether two groups are different from one another.
A t test is the most commonly applied when the test statistic would follow a normal distribution if the value of a scaling term in the test statistic were known. This test is described in a dedicated chapter. A t test also known as student s t test is a tool for evaluating the means of one or two populations using hypothesis testing.
A t test compares the means of two groups.
If you have two groups with paired observations e g before and after measurements use the paired t test. And the data at least approximately follow a normal distribution. The independent samples t test comes in two different forms. The t test is any statistical hypothesis test in which the test statistic follows a student s t distribution under the null hypothesis.
