Related Procedures

The paired-samples t test is appropriate whenever two related sample means are to be compared. The difference scores are assumed to follow a reasonably normal distribution, especially with respect to skewness. Before running the t test, you can assess the distribution of difference scores by examining the histogram of a computed difference variable. Test variables with extreme or outlying values should be carefully checked; boxplots can be used for this.

If you compute the difference between the paired variables, you can alternatively use the One-Sample T Test procedure.