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. |