Table of Contents### Calculating Measures of Variation

Entire Site

Descriptive statistics such as the mean, median, and mode fall under what statisticians call measures of central tendency (or sometimes measures of location). These numbers are designed to give you some idea of what constitutes a “typical” value in the data set.

This is in contrast to the so-called measures of variation (or sometimes measures of dispersion), which are designed to give you some idea of how the values in the data set vary with respect to one another. For example, a data set in which all the values are the same would have no variability; in contrast, a data set with wildly different values would have high variability. Just what is meant by “wildly different” is what the statistical techniques in this section are designed to help you calculate.