# Statistics - (Data|Data Set) (Summary|Description) - Descriptive Statistics

### Table of Contents

## About

Summary are a single value summarizing a array of data.

They are:

- selected
- or calculated through reduction operations.

They are an important element of descriptive analysis

One of the most important tools for summarizing data is to display it visually. See the Anscombe's quartet to understand why ?

From a summary, you can make an inference on a individual without looking at the distribution

Have a look at the distribution before jumping to the summary (in order to not make a stereotype)

Same as: Function - (Aggregate | Aggregation)

## Articles Related

## Statistics

### Measures of center

In order to summarize a set of data, we want to use one single number or value to describe where it is centred.

This single value can be calculated through one of the following (statistic|measure) of center:

### (Spread|Variability|Dispersion)

Another important element of a data set is how it is spread.

Measures of spread:

- range,
- inter-quartile range,

### Others

- count (sample size)
- minimum
- maximum
- frequency

### Library

Apache Math Package specifically DescriptiveStatistics