Correlation and dependence
lastmod 2018-08-17created 2014-10-231 edits
Correlation Analysis is a method in probability theory and statistics for analyzing whether two variables have some linear relationship. Two variables can range from being independent of each other to being correlated with each other, and the strength of the relationship between the two variables is called Correlation (Correlation coefficient). In correlation analysis, the population correlation coefficient ρ is used as the unit expressing the degree of correlation.
The Correlation coefficient, which measures the degree of correlation, only shows how closely two variables are associated; it does not explain causation. Whether there is a cause-and-effect causal relationship between two variables can be checked through regression analysis, which shows the direction and degree of the causal relationship and a mathematical model.