Parametric statistics are used when our data are measured on approximately interval, interval, or ratio scales of measurement. No distinctions are made among these scales of measurement, although all parametric statistics have assumptions that must be met before proceeding with statistical analysis. The parametric statistics that we learned in class are listed below. This is not a complete list -- we did not learn advanced statistical techniques.

In order to choose among these tests, we must next determine the number of samples in the study design and the relationship between samples.

Once we have reviewed our options, the next step is to consider the study design.