### Choosing a T-Test Function

EZAnalyze
contains three t-test options; a one sample, paired samples, or independent
samples t-test. Each is briefly described below, with a link for going
directly to the help topic for each type of t-test.

One
Sample T-Test -
appropriate for use when you are comparing a value that is known in
the population to your data. For example, if you want to know how students
in your school compare to students in the US on the SAT, you would
use this test because we know the national average SAT score is 1000
(or perhaps 1500 if you use all three sections).

Paired
Samples T-Test - use this when you want to compare data that are
in two columns from the same person. This is a "repeated measures" t-test
because appropriate use requires that the same person contributed
scores to both measures. An excellent example of this is to see if
there is
a difference between pretest scores and posttest scores
after some kind of intervention.

Independent
Samples T-Test - the most common type of t-test, this is appropriate
for use when you want to see how two different groups performed on
some dependent measure. For example, if you want to see if boys and
girls have significantly different attendance rates at your school,
you would use the independent samples t-test to get your answer.

Go to Index of Help Topics