ABSTRACT
There are three different types of t-test: the one-sample t-test, the independent samples t-test and the paired samples t-test. The one-sample t-test compares a sample mean with some hypothesized mean. The other two t-tests are used to compare the means for an interval or ratio scale variable between two samples. The variable distinguishing the samples is the independent variable, while the interval or ratio scale variable hypothesized to be influenced by sample is the dependent variable. The main difference between independent and paired samples t-tests is that the independent samples t-test compares independent samples whereas the paired samples t-test compares related samples. Recall from Chapter 7 that independent samples are drawn from different groups of individuals who we wish to compare. For example, if we were comparing the mean of some variable between males and females, gender would be the independent variable with the male and female groups forming independent samples. Related samples are drawn from the same group of individuals under different conditions. For example, if we were comparing the mean of some performance variable between teams’ home records and their away records, venue would be the independent variable with home and away being two conditions related to the set of teams included in the study.
