# Correlation

Measures the strength (and the significance) of the relationship between two data sets.

## Correlation Coefficient in NumXL

In statistical terms, correlation is a method of assessing a possible two-way linear association between two continuous variables. Correlation is measured by a statistic called correlation coefficient, which represents the strength of the putative linear association between the variables in question. It is a dimensionless quantity that takes a value in the range −1 to +1.

There are two main types of correlation coefficients:

1. Product moment correlation coefficient (e.g. Pearson)
2. Rank correlation coefficient (e.g. Spearman, Kendal-tau, etc.).

The correct usage of each correlation coefficient type depends on the types of variables being studied. For instance, Pearson's correlation summes the variables pair are normally distributed, while Spearman's correlation coefficient makes no such assumption.

With NumXL functions, you can use your data in Excel, and calculate correlation coefficients using different methods: Spearman, Pearson, and Kendal-tau. Furthermore, NumXL compute the standard error in the estimate correlation coefficient, so you go one step further, and quantify its statistical significance.

## Correlation Function Correlogram tutorial

The correlogram functionality automates the statistical analysis of the serial correlation...