Summary statistics
easiest way to approach the subject of
summary statistics is to focus on what we have and what we want to achieve:
- We have a set of observations which we want to summarize.
- We want to communicate as much as possible as simply as possible.
Statisticians commonly try to describe the observations in
- a measure of location, or central tendency, like the arithmetic mean
- a measure of statistical dispersion like the standard deviation
- a measure of the shape of the distribution like skewness or kurtosis
There are other alternatives, of course. The
median,
mode, and
interquartile mean are both measures of location. To describe the
statistical dispersion, we can use the
statistical range, the
interquartile range, or the
absolute deviation.
The Gini coefficient was originally developed to measure income inequality, but can be used for other purposes as well.
back to statistical theory -- summarizing statistical data